GIFT OF 
 JANE KoSATHER 
 
Huxley Memorial Lectures 
 


Huxley 
 Memorial Lectures 
 
 to the 
 
 University of Birmingham 
 
 With an Introduction by 
 
 Sir Oliver Lodge, D.Sc., F.R.S. 
 
 Birmingham 
 
 Cornish Brothers Ltd 
 
 Publishers to the University 
 
 39 New Street 
 
 1914 
 
-. 
 . ' -.- 
 
Contents 
 
 Pages 
 
 Introduction by Sir Oliver Lodge ... ... 38 
 
 Huxley by Sir Michael Foster ... ... 9 43 
 
 Huxley and Natural Selection by Professor E. B. 
 
 Poulton, F.R.S. .. ... ... 4551 
 
 Rationalism and Science in Relation to Social 
 
 Movements by Professor Percy Gardner ... 53 97 
 
 Life and Consciousness by Professor Henri 
 
 Bergson ... ... ... ... 99 128 
 
 Pleochroic Haloes (illustrated) by Professor John 
 
 Joly, F.R.S. ... ... ... ... 129160 
 
 338412 
 
INTRODUCTION. 
 
 A few years ago a Governor of the University 
 of Birmingham, admiring the genius of Huxley, 
 and wishing to do something to perpetuate the 
 memory of his association with Birmingham, gave 
 an endowment for the perpetual provision of a 
 Lecture to be given annually, to the assembled 
 University and its friends, under the title of " The 
 Huxley Lecture." No conditions were attached, 
 and no subject was prescribed, save that it should 
 be on some theme which might have interested 
 Huxley a scope sufficiently wide for anything. 
 
 It seemed appropriate that the first one or two 
 lectures should deal with some aspect of Huxley 
 himself, and his friend Sir Michael Foster was 
 asked to give the first lecture on the more personal 
 side. No claim was made on the lecturers as 
 to publication, nor was the discourse even written 
 in every case. Those that were written often 
 appeared subsequently in some serial publication 
 and thus became more widely accessible. 
 
4 INTRODUCTION 
 
 ; ;" -Recently it has been thought desirable to col- 
 lect such of these lectures as were available and 
 publish them together ; and thanks are due to the 
 owners of the copyright for the permission freely 
 given for this local re-publication. 
 
 The connection of Huxley with Birmingham 
 may not be generally known. But in the year 
 1874 he came down to give an address on the 
 occasion of the presentation of a statue of Joseph 
 Priestley to the town of Birmingham the town 
 in which that scientific pioneer and political 
 philosopher had been ill-used, his property 
 destroyed, and himself expelled, at the time 
 of the Birmingham "Church and King" Riots 
 in 1791. The address which Huxley de- 
 livered on that occasion is the first of the col- 
 lected Essays re-published by Messrs. Macmillan 
 in the Eversley Series. The volume containing 
 this particular address is called " Science and 
 Education," it appeared in 1893 and has been 
 many times reprinted. 
 
 Huxley came to Birmingham also to lay the 
 foundation stone of Mason College, which was 
 the predecessor and parent of the University; 
 and when that College was opened which it was 
 in 1880, under the early title " Sir Josiah Mason's 
 Science College " Huxley came again and 
 delivered the Inaugural Address; an Address 
 which is published in the volume already men- 
 tioned, under the title " Science and Culture," 
 
INTRODUCTION 5 
 
 The complete list of the Huxley Lectures so 
 far given is as follows : 
 
 Date. 
 
 Lecturer. 
 
 Title. 
 
 1 
 
 16th March, 1904 
 
 Sir Michael Foster .. 
 
 "The Work and Influence of 
 Thomas Henry Hniley." 
 
 
 
 
 (Published in The National Re- 
 
 
 
 
 view, Vol. 43, 1904.) 
 
 2 
 
 23rd March, 1905 
 
 Prof. E- B. Poulton .. 
 
 "Thomas Henry Huxley and the 
 Theory ef Natural Selection. 1 ' 
 
 
 
 
 (Published [not in .full] in The 
 
 
 
 
 Scientific A merican Supple" 
 
 
 
 
 ment, Vol. 59, April, 1905.) 
 
 3 
 
 27th Nov., 1907 
 
 Prof. Sir J.J.Thomson 
 
 "The Influence of Recent Dis- 
 
 
 
 
 coveries in Electrioityon ourOon- 
 ceptions of Matter and Ether." 
 
 4 
 
 25th Nov., 1908 
 
 Prof. Sir Ronald Ross 
 
 "Malaria." 
 
 5 
 
 1st Deo., 1909 
 
 Prof. William Bateson 
 
 " Mendelian Heredity. 1 ' 
 
 6 
 
 23rd Nov., 1910 
 
 Prof. Percy Gardner.. 
 
 " Rationalism and Science in rela- 
 
 
 
 
 tion to Social Movements.' 1 
 
 7 
 
 29th May, 1911 
 
 Prof Henri Bergs on 
 
 "Life and Consciousness." 
 
 
 
 
 (Published in The Hibbert Journal 
 
 
 
 
 October, 1911.) 
 
 8 
 
 30th Oct., 1912 
 
 Prof. John Jo ly 
 
 "Pleochroic Haloes.' 
 
 
 
 
 (Published in Bedrock, Jan., 1913). 
 
 9 
 
 8th Deo., 1913 
 
 Sir Arthnr Evans 
 
 "The Ages of Minos." 
 
 And of these, Numbers i, 2, 6, 7, and 8 are here 
 reproduced; the others, for various reasons, are 
 not available. 
 
 Before leaving the subject of Huxley a man 
 for whom I personally had a profound admira- 
 tion let me take the opportunity of emphasising 
 the unfairness, as well as the illiterateness, of 
 claiming him as a materialistic philosopher, or as 
 an advocate of philosophic Materialism, merely 
 because he set his face in the direction of a 
 
6 INTRODUCTION 
 
 rational interpretation of nature, and combated 
 many intellectual errors with which the theology 
 of that day had, through careless thinking and 
 uncritical exegesis, been sorely tainted. The 
 mistake is made though that is no excuse be- 
 cause he emphasised, as Newton did, the duty of 
 scientific men to study and emphasise every 
 extension of the province of what we call 
 " Matter " and " Force " ; and because he urged 
 that " the growth of science, not merely of physi- 
 cal science, but of all science, means the demon- 
 stration of order and natural causation among 
 phenomena which had not previously been 
 brought under those conceptions." 
 
 Doubtless the claim that Huxley was a sup- 
 porter of philosophic Materialism, as against 
 Idealism, is only made by half educated people ; 
 but such persons are numerous ; and hence for the 
 present it is desirable to take every opportunity 
 of pointing out that the contention is untrue, and 
 was always resented by Huxley himself. The fol- 
 lowing quotation from his 1886 essay " Science 
 and Morals," now included in the volume called 
 " Evolution and Ethics," will suffice to show how 
 he regarded such a rhetorical accusation. 
 ^Evolution and Ethics, p. 129-130.] 
 
 " I understand the main tenet of Material- 
 ism to be that there is nothing in the universe 
 but matter and force; and that all the 
 phenomena of nature are explicable by de- 
 duction from the properties assignable to 
 
INTRODUCTION 7 
 
 these two primitive factors. That great 
 champion of Materialism whom Mr. Lilly 
 appears to consider to be an authority in 
 physical science, Dr. Biichner, embodies this 
 article of faith on his title-page. Kraft und 
 Stoff force and matter are paraded as the 
 Alpha and Omega of existence. This I 
 apprehend is the fundamental article of the 
 faith materialistic; and whosoever does not 
 hold it is condemned by the more zealous of 
 the persuasion (as I have some reason to 
 know) to the Inferno appointed for fools or 
 hypocrites. But all this I heartily dis- 
 believe ; and at the risk of being charged 
 with wearisome repetition of an old story, I 
 will briefly give my reasons for persisting in 
 my infidelity. In the first place, as I have 
 already hinted, it seems to me pretty plain 
 that there is a third thing in the universe, to 
 wit, consciousness, which, in the hardness of 
 my heart or head, I cannot see to be matter, 
 or force, or any conceivable modification of 
 either, however intimately the manifestations 
 of the phenomena of consciousness may be 
 connected with the phenomena known as 
 matter and force. In the second place, the 
 arguments used by Descartes and Berkeley 
 to show that our certain knowledge does not 
 extend beyond our states of consciousness, 
 appear to me to be as irrefragable now as 
 they did when I first became acquainted with 
 
8 INTRODUCTION 
 
 them some half-century ago. All the 
 materialistic writers I know of who have tried 
 to bite that file have simply broken their 
 teeth. But if this is true, our one certainty 
 is the existence of the mental world, and that 
 of Kraft und Stoff falls into the rank of, at 
 best, a highly probably hypothesis." 
 With this short introduction I leave the Huxley 
 Lecturers to speak for themselves. 
 
 OLIVER LODGE. 
 March, 1914. 
 
HUXLEY* 
 
 By Sir Michael Foster. 
 
 Casting round for a theme which might fitly 
 be the subject of this first Huxley Lecture which 
 the University of Birmingham, doing me great 
 honour, has asked me to deliver, I bethought me 
 of the wish of the generous founder of the Lec- 
 tures that, if possible, this first lecture should be 
 entrusted to some one who knew Huxley, not by 
 his writings and public utterances only, but in a 
 closer way, through being numbered within the 
 happy circle of his inner friends. That wish 
 seemed to me an invitation to devote this first 
 lecture to the man himself and his work; and, not 
 without fear and trembling, I have ventured to 
 guide myself by such an invitation. I will not 
 attempt to dwell on any details of his life; these 
 can be, ought to be, and probably are, known to 
 you all. I must content myself with some 
 thoughts about his ways, his views, and his aims. 
 As I go along I can only touch lightly, and in a 
 passing way, on some of the many and varied 
 problems which are started by the consideration 
 of his manifoldly active life; these, or at least 
 many of them, will doubtless be fully dealt with 
 
 * Being the firit " Huxley " lecture of the University of 
 Birmingham, delivered on March i6th, 1914. 
 
io HUXLEY MEMORIAL LECTURES 
 
 by the able men who will succeed me in the com- 
 ing years. Following in his steps, I shall, even 
 at the risk of giving offence, try to speak plainly 
 and straightforwardly when I come to touch on 
 themes with which he dealt, about which we all 
 feel so deeply. 
 
 Every one in this world, at least every one of 
 whom others need take count, has a dominant 
 note. If I ask myself, what was Huxley's 
 dominant note ? I find myself answering without 
 hesitation a love of knowledge, an ever-present 
 never-satisfied desire to know. There are many 
 ways of knowing; of these two stand out as dis- 
 tinctive ways, offering a contrast the one to the 
 other. One way of knowing lies in gathering up, 
 in sweeping into the mind, all the grains of 
 information which happen to be lying around. 
 This is, as it were, the greediness of multifarious 
 knowledge, conspicuous in the child, but also 
 common in the adult; it is that yearning to know 
 everything that is going on which is the main- 
 spring of daily talk and makes the fortunes of the 
 Press. Such a greed of knowledge Huxley 
 possessed ; such a way of knowing he followed to 
 a remarkable degree ; nothing touched him, noth- 
 ing even came near to him but what he strove to 
 lay hold of it. And he found such profit to him- 
 self in this kind of knowledge that he laid it 
 down as an axiom of education that every one, so 
 far as possible, should be led towards knowing 
 something of everything. 
 
HUXLEY ii 
 
 Another way of knowing is, when a thing is to 
 be known, to know it fully and exactly; to be 
 aware where the known begins, and where it ends ; 
 to be sure and clear what the terms, the symbols 
 used in the knowledge, really mean ; to have the 
 component parts of each bit of knowledge so 
 arranged that it may fitly serve as the instrument 
 of clear and exact thinking. This is the kind of 
 knowledge in which Huxley, above most men, 
 found his heart's content. We know from his 
 life that his love of machinery led him at one time 
 to wish to be an engineer. What fascinated him 
 in a machine was its completeness and perfection, 
 the fitting together of all its parts to a common 
 end, the feature that, if well and truly made, it 
 could at any time without harm be taken to pieces 
 and put together again. He demanded that, so 
 far as possible, each piece of knowledge of which 
 he had to make use should have the complete- 
 ness, the perfection, the clean fit of a machine. 
 With such exact and sharply defined knowledge 
 alone could he feel that he was thinking clearly. 
 
 Some minds there are which find a charm in 
 indistinctness ; impressionists in matters of know 
 ledge, truth seems to them to have the greater 
 charm when its features are softened by a sur- 
 rounding mist of doubt and uncertainty; placed 
 before them in sharp, clear outlines, it offends 
 them as being hard and crude. It was not so with 
 Huxley. He felt as fully as any one the beauty 
 born of dimness which rounds off with softness 
 
12 HUXLEY MEMORIAL LECTURES 
 
 the features of the far-off horizon where the 
 known makes clouds out of the unknown; but to 
 him that beauty belonged to that far-off horizon 
 alone; in things within the focus of intellectual 
 vision beauty lay in clear and well-defined 
 images; whatever came before him with its out- 
 lines blurred by imperfect comprehension, loose 
 expression, and vague presentation, was to him 
 something ugly. It was this combination of 
 wide and varied knowledge with a love of exact 
 and rigorous thinking which gave to him, so it 
 seems to me, his worth and influence as a man of 
 science. Circumstances led him to find a sphere 
 for his scientific activity in that branch of science 
 which, under the name of Comparative Anatomy, 
 or Animal Morphology, deals with the multi- 
 farious forms of the living beings which we call 
 animals. His early wish had been to become an 
 engineer, busying himself with machines; turned 
 away from this by fate, he had wished to give 
 himself to the somewhat allied science of physi- 
 ology, which deals with animals as machines. 
 But this also was not to be; he was driven to 
 devote himself to a branch of science which was 
 not his first love, and for which he was in some 
 respects less fitted. Any lack of fitness, however, 
 which there might have been was soon lost sight 
 of amid the many and great products of his 
 labours. 
 
 In each science progress appears as a series of 
 steps, each step being marked by the appearance 
 
HUXLEY 13 
 
 of some work of prominent worth, the intervals 
 between each such work being filled up with the 
 products of a number of intermediate less signifi- 
 cant labours contributing to the progress, but in a 
 less effective manner. The work whose appear- 
 ance thus marks a step, whether it be what is 
 called a discovery, or whether it be the setting 
 forth of a new view or theory, is often spoken of 
 as a classic work; it is remembered, and referred 
 to afterwards again and again, while the less 
 significant labours are forgotten. For many 
 years Huxley continued to produce in Compara- 
 tive Anatomy, including Palaeontology, for to 
 this also by sheer force of circumstances he was 
 led to direct his attention, works which are en- 
 rolled in the list of scientific classics. The earlier 
 of these, those on jelly fish, molluscs, and other 
 oceanic animal forms, were done as almost 
 apprentice work, done while he was as yet a mere 
 youngster, serving as a surgical subaltern on 
 board the Rattlesnake in an exploring expedition 
 to the Australian seas. These and the rest are 
 to be found in the four large volumes of scientific 
 memoirs which his publishers, Messrs. Macmillan, 
 brought out as their contribution to the memory 
 of his name. Of the many memoirs contained in 
 those volumes a large number are now and always 
 will be spoken of as classic memoirs. To the 
 man of science those volumes alone are adequate 
 proof of how much Huxley did to push forward 
 the science among the followers of which fate had 
 led him to enrol himself. 
 
i 4 HUXLEY MEMORIAL LECTURES 
 
 All real scientific work has this distinctive 
 mark : it is reproductive and fertile, it gives birth 
 to other scientific work following upon itself, and 
 that in two ways. It is reproductive in the way 
 of the parentage of fact; each new discovery of 
 real worth becomes the starting-point of new 
 inquiries, leading in turn to new discoveries. It 
 is also reproductive in the way of the parentage 
 of spirit and of method; and this parentage is, 
 perhaps, the more fertile of the two. The new 
 discovery, the new fact made known, the new view 
 put forward and commanding assent, is, often at 
 least, the outcome of a new way of looking at 
 things; and that new way of looking at things 
 spreads among those who are working at the same 
 subject. Again and again the appearance of a 
 memoir or a book has acted like a magnet, turn- 
 ing men's minds from looking in one direction and 
 making them look in another. Huxley's work in 
 Comparative Anatomy or perhaps I ought to 
 use a wider phrase, and say in Biology was of 
 the reproductive kind, and reproductive especi- 
 ally by way of parentage of method. 
 
 When he sailed away from England on board 
 the Rattlesnake much, if not nearly all, the work 
 which was being done, and for many years past 
 had been done, in England at least, in the way of 
 enlarging our knowledge of animal forms, con- 
 sisted, on the one hand, in the careful but dull 
 accumulation of facts, unillumined by any thought 
 as to what was the real meaning of the facts so 
 
HUXLEY 15 
 
 industriously gathered together ; and, on the other 
 hand, in the putting forward of nebulous and fan- 
 tastic theories as to that meaning, theories not 
 springing out of the consideration of the facts 
 themselves, but coming from elsewhere, the off- 
 spring of foreign ideas, thrust into the facts from 
 the outside. Huxley's mind, with its clear and 
 exact way of thinking, with its tendency to look 
 upon a machine as a model of excellence, rebelled 
 at the very outset against these vague and mystic 
 theories, the hybrid products, it seemed to him, 
 of careful observation and loose thinking. He 
 strove to replace them by ideas more justly 
 deserving to be spoken of as scientific. He saw 
 how in the sister physical sciences progress con- 
 sisted in the marshalling of facts under laws the 
 knowledge of which came through observation 
 and experiment, and which indeed were but the 
 expression of elaborated observation; and he set 
 himself to the task of making the same fruitful 
 method dominant in biology. The very first 
 papers which he sent home to England from the 
 far-off Southern Seas not only added largely to 
 new knowledge, but served as striking lessons in 
 the new way of attacking biological problems; 
 these were in turn followed by others, all exempli- 
 fying the value of the new method; and though 
 the older men were in two minds about them, dis- 
 liking the new ideas but admiring the ability with 
 which they were put forward, the younger men 
 received them gladly and at once. Under Hux- 
 
16 HUXLEY MEMORIAL LECTURES 
 
 ley's lead a new school of biological inquiry came 
 into being. Thus from the very beginning of his 
 career, by mere force of his efforts to get for him- 
 self a clear view of the things with which he had 
 to deal, to gain a firm ground from which he could 
 push forward into the unknown, Huxley, without 
 thought of others, became a teacher of inquirers. 
 But he could not do without thinking of others. 
 To his strong desire to know fully, and to think 
 clearly for himself, there was added a no less 
 strong desire that others also should know fully 
 and should think clearly. Not content, as he well 
 might have been, with being a teacher by 
 example, he, very soon after his return to Eng- 
 land, became a teacher by precept. While some 
 of us of the biological craft are painfully aware 
 of how much science would have gained had the 
 stream of energy which later on spread over such 
 wide fields been kept in its earlier and narrower 
 channel, we must admit that the world at large 
 would thereby have been greatly a loser. Hux- 
 ley became a teacher by precept, set himself to 
 the task of bettering the way in which men should 
 be taught. He began, naturally began, with the 
 teaching of what I may call the professional few, 
 with the training of those who enter upon the 
 study of science, knowing that a knowledge of 
 science must be, in one way or another, an 
 important factor in their future life; but he very 
 soon passed on to the wider task of teaching the 
 general many. In both these kinds of teaching 
 
HUXLEY 17 
 
 he held fast to the conception which had guided 
 him in his own intellectual development, and 
 which he formulated in the saying that the goal of 
 teaching, that to which the face should be turned, 
 though it might not be reached, should be to make 
 the learner know something of everything and 
 everything of something. The one stimulated 
 intellectual appetite and awakened the innate 
 capacities and tendencies of the mind, while at 
 the same time it secured a broad basis on which 
 to build. The other furnished the only means of 
 developing that power of clear and exact think- 
 ing which was the main end of teaching, since 
 every teaching which failed to secure this was in 
 vain, and was potent in the measure that it did 
 secure it. This view of the need of an effort to 
 secure at one and the same time breadth and 
 exactitude he carried into his teaching of science. 
 This is seen clearly in the mode of teaching 
 biology which he advocated. 
 
 The science of biology is split up into several 
 parts. There are beings whose characters lead 
 us to call them animals and others which we call 
 plants, and the differences between the two are 
 many and great. A living being, again, be it 
 plant or animal, on the one hand, presents 
 phenomena of form which have to be studied in 
 a particular way, and so furnish the subject- 
 matter of the science of anatomy or morphology. 
 On the other hand, it presents phenomena of 
 action, of function, which have to be studied in 
 
i8 HUXLEY MEMORIAL LECTURES 
 
 another way, and which furnish the subject-matter 
 of the science of physiology. Further, every 
 living being may be studied from the point of 
 view of how it came to be, how it is related to other 
 beings, and what part it plays in the general 
 economy of nature. Biology is thus split up into 
 several branches, several more or less inde- 
 pendent sciences, and the man who looks forward 
 to advancing knowledge in any one of them finds, 
 and finds increasingly as knowledge advances, 
 that he must narrow his efforts to one of them, 
 or even to a part, perhaps a small part, of that. 
 And the temptation is natural and strong for the 
 learner to turn to the narrowing early, even per- 
 haps at the beginning, pursuing his narrow path 
 from the outset in ignorance of what is going on 
 around him. Yet these several sciences, these 
 several branches of biology, are not really and 
 wholly independent : they touch each other, here 
 and there, again and again. Hence Huxley 
 and all of us, I venture to think, will agree that 
 he was right maintained that, necessary as it 
 may be for the student to narrow his outlook 
 when he is well on his way, he will work all the 
 more fruitfully, gaining results of all the higher 
 value if, before passing through the straight gate 
 to his ultimate narrow path, he gets to know what 
 other paths there are, what are their features, and 
 whither they lead. Hence he introduced a teach- 
 ing of biology, in which as many as possible of all 
 kinds of biological problems, and not one kind 
 
HUXLEY 19 
 
 only, should be presented to the student. In that 
 way he looked to get a breadth which could not 
 otherwise be gained. Exactitude he trusted to 
 secure at the same time that he was striving for 
 breadth by the method of teaching. Selecting a 
 few themes, and a few only, from the several 
 branches of biology, and these so far as possible 
 of an elementary, fundamental character, he 
 strove to make the student grasp each of these as 
 fully and as exactly as was within his power. And 
 he taught through the eyes as well as through the 
 ears. The younger generation to-day can per- 
 haps hardly realise to what an extent, thirty or 
 forty years ago, in science teaching, especially in 
 biological teaching, oral exposition and the read- 
 ing of books still supplied the dominant means of 
 learning. Biological laboratories were then only 
 beginning to be. Huxley was from the first in- 
 sistent that a firm grasp, an exact grip, of the 
 phenomena and laws of nature could only be 
 gained by him who had been led to see the phe- 
 nomena for himself, and to work out through 
 observations and experiments conducted by him- 
 self the problems presented. Arguments, discus- 
 sions, apt illustrations, lucid exposition, all these 
 were needed to make good the lesson; but they 
 were as so much beating the air, unless they dealt 
 with things which had been really seen and actu- 
 ally handled. 
 
 It was not in the teaching of biological science 
 alone that he urged this marriage of breadth with 
 
20 HUXLEY MEMORIAL LECTURES 
 
 exactitude; he advocated it as the proper mode 
 of training for every kind of career. Begin with 
 a broad basis, with a basis as broad as the mental 
 power of the student can compass, but even in 
 laying down the basis hold fast to exactitude. 
 Breadth without the clearness and firmness which 
 comes from direct sight and exact thought merely 
 breeds mental flabbiness, a treacherous basis to 
 build on. Some minds cannot spread themselves 
 over a large field without losing touch with the 
 exact and the real ; don't attempt to stretch such 
 minds too much; in the case of these be content 
 with a basis of smaller area. Having laid a 
 foundation as broad as the mind of the learner 
 will allow, a foundation of simple elementary 
 truths, build on this the teaching of higher, more 
 difficult matters. As you ascend you will find 
 that, in order to secure that full comprehension, 
 that exact and clear thought which you aim to 
 secure, the limits of mental power will compel 
 you continually to narrow the range. Be not dis- 
 heartened at this. Knowing that you have the 
 broad basis below, do not fear to narrow the range 
 as you raise tier on tier so long as the demands of 
 exactitude call for it. As you ascend do not 
 spoil the compactness of your product by attempt- 
 ing to put wide, loose wrappings round the solid 
 core. Be .content that the product of your teach- 
 ing should be a cone, such as may be used as an 
 intellectual missile, penetrating because its point 
 is narrow, effective because its base is broad. 
 
HUXLEY 21 
 
 Such, in broad outlines, seem to me to have 
 been Huxley's views as to the right teaching of 
 the professional few. But in this matter of teach- 
 ing his heart went out, beyond the limited circles 
 of professions, to the great " general many." He 
 put his hand to the work of rightly teaching these 
 also. 
 
 Nothing, perhaps, in his whole career is more 
 striking than his coming out in 1870 from the tent 
 of the Professor to take his part in the popular 
 battles of the London School Board. Never, 
 perhaps, was he busier than he was at this time ; 
 his hands were full with scientific research and 
 scientific teaching; they were full with scientific 
 administration. Yet he knew that he had some- 
 thing to say about the teaching of the people; he 
 refused to keep for the sect of science that which 
 he felt was meant for mankind, and came forward 
 to take his part in what he believed to be a task 
 of great moment. He did not shrink from enter- 
 ing upon that which is, perhaps in many ways, 
 most foreign to a scientific career, a popular con- 
 test; for, though few could appraise more truly 
 than he the value of the thought of the few who 
 know, none were more ready than he to accept the 
 judgment of the many who feel. And the elec- 
 tors returned to him the confidence which he had 
 placed in them. 
 
 He carried into the School Board the same 
 views as to right teaching which had guided him 
 in the academic lecture-room and in the labora- 
 
22 HUXLEY MEMORIAL LECTURES 
 
 tory, though the difference in the subject matter 
 and the occasion made a difference in the form in 
 which these were put forward. In the academic 
 lecture-room the professional student is taught in 
 part only; he comes to it already fashioned in 
 part. In the school the child has to be taught 
 wholly and from the beginning ; his whole nature 
 is placed in the teacher's hands. Yet the right 
 method of teaching is in both cases at bottom the 
 same. Throughout Huxley's system of profes- 
 sional teaching, which I have attempted to de- 
 scribe, the effort to combine breadth of view with 
 clearness and exactitude of insight, there ran the 
 fundamental idea that the real goal of profes- 
 sional teaching is not to fill the head with stores 
 of knowledge, however accurate, however well 
 adapted for professional use, but to lay the 
 foundations of, and to develop as far as possible, 
 all those qualities which go to make up the effec- 
 tive scientific professional character. And the 
 goal of school teaching which Huxley put before 
 him was the development of the whole nature, the 
 building up of a fit character in the schoolboy or 
 schoolgirl. If in professional teaching it was 
 needful to keep this goal steadily in view, it was, 
 in his eyes, a thousand times more needful to keep 
 it in view at the school in the few, but pregnant, 
 years during which the lad or lass comes under 
 the moulding hands of the teacher. In the 
 school, above all other places, everything should 
 be made subservient to this great end. 
 
HUXLEY 23 
 
 The striving for this goal may be seen in all 
 Huxley's School Board work. As I shall shortly 
 have occasion to insist, he refused to split up 
 human nature into this and that part physical, 
 intellectual, moral to be treated apart in dif- 
 ferent ways. To him human nature was one and 
 indivisible, to be treated in all its parts according 
 to the same fundamental method. Hence his 
 advocacy of physical training, not as a mere\ 
 appendage to, but as an essential part of, school 
 work. In the narrower training of the grown-up, 
 or nearly grown-up, biological student he laid no 
 little stress on physical training, the training of 
 the eye, the ear, and the hand; for, the clearer 
 the sight, the sharper the hearing, and the readier 
 the touch, the greater the firmness with which the 
 student can lay hold of the phenomena of nature, 
 the more surely he can gain the basis needed for 
 exactitude of thought and judgment. In the 
 broader training of the growing child, physical 
 training seemed to him to be one of the first of 
 needs, not for the sake only of what some call the 
 body, but for the sake of the whole child. 
 
 The same desire to reach character guided him 
 in his selection of subjects to be taught and of 
 methods of school teaching. It seemed to him 
 that the primary object of all teaching of the 
 young must be to awaken the mind, to rouse the 
 attention, to excite the desire to know more. And 
 though he knew that a good teacher has the power 
 to accomplish this, whatever be the subject which 
 
24 HUXLEY MEMORIAL LECTURES 
 
 he handles, while a bad teacher may fail to do 
 this with any subject, he sought for a basis of early 
 education in the subjects likely of themselves, 
 without taxing the teacher, to interest the scholars 
 and stimulate them to mental effort. These he 
 found in common things, in things with which the 
 children came into touch, things of which they 
 heard, things which they might use in daily life. 
 He gave what is sometimes called useful know- 
 ledge a large share in school life, not simply be- 
 cause it was useful, though this he did not despise, 
 but because it offered the best opportunities for 
 awakening the young mind and at the same time 
 could be so taught as to provide the desired disci- 
 pline and training of the mind thus awakened. 
 
 It was this earnest wish of his to make the 
 school the means of moulding the whole charac- 
 ter, and not of developing this or that part of it at 
 the expense of the rest, that led him to take a step 
 which has been much criticised, and, if I may 
 venture to say so, much misunderstood to advo- 
 cate the use of the Bible as part of the common 
 school-lessons in the School Board schools. Of 
 nothing was he more sure than this, that that 
 schoolmaster fell short of his high calling who 
 failed to guide his pupils to know the right from 
 the wrong, and to follow the former in every- 
 thing, not only in reading, writing, and arithmetic, 
 in history, geography, and the other kinds of 
 knowledge which he and they handled, but also 
 and no less so in the treatment of the body and 
 
HUXLEY 25 
 
 in the conduct of life. The character which the 
 school had to build up could, in his view, be noth- 
 ing more than a broken fragment, a fragment 
 whose broken edges were dangerous if, in attempt- 
 ing to build it up, the moral phenomena and the 
 moral laws of the universe were wholly left out of 
 sight. 
 
 But in seeking for a teaching which should thus 
 build up the whole character he was met by a 
 great difficulty. He himself had long been con- 
 vinced that the conduct of life might be guided 
 by a morality and inspired by a religion having 
 no part whatever in the theological doctrines of 
 any Church, whether Roman, Anglican, or any 
 other. His own life had been guided by that 
 morality and inspired by that religion. He be- 
 lieved that those who thought with him on this 
 matter were increasing in numbers everywhere 
 and would in the end become dominant. At the 
 same time he recognised that in the face of the 
 prevailing influence of the several forms of the 
 Christian Church, and in the presence of powerful 
 traditions, inwrought into the very national life, 
 to teach such a morality and such religion in the 
 common school called for teachers possessing 
 convictions which were rare and powers which 
 were still rarer. On the other hand, he recognised 
 in the Bible, ingrained into the lives and dear 
 to the hearts of so many, a most potent instrument 
 for inculcating the moral lessons which he desired 
 to see inculcated and for inspiring the moral 
 
26 HUXLEY MEMORIAL LECTURES 
 
 aspirations which he desired to see inspired. 
 With its beautiful lauguage and its old associa- 
 tions, it seemed to him a means of awakening the 
 moral sense and pointing out the duty of man, 
 such as he could not find elsewhere, such at least 
 as he could not wisely put on one side. 
 
 He was well aware that in it the great moral 
 lessons which he sought to enforce were closely 
 wrapped up in other things, were, indeed, con- 
 veyed by means of teachings, many of which he 
 was convinced were erroneous, some of which he 
 held to be mischievous. But he thought that this 
 difficulty was largely met by the decision that the 
 Bible was to be taught in the school in such a way 
 as to be free from dogma. And, weighing one 
 thing against the other, he accepted Biblical 
 teaching as what in the language of the world is 
 called a practical compromise. He was the more 
 inclined to this step because he believed and 
 hoped that it was the beginning of other things. 
 He took it for granted that this Biblical teaching 
 would be placed in the hands of laymen, and 
 moulded by the thoughts of laymen. Laymen 
 would, he conceived, be more and more drawn to 
 his own way of thinking, and out of the teaching 
 which he had helped to institute would be evolved 
 another simpler ethical teaching free from all 
 theological conceptions. He failed to realise 
 that to make the Bible the chosen and sole means 
 of enforcing moral lessons strengthened the ties 
 binding the teaching of moral duties to the accept- 
 
HUXLEY 27 
 
 ance of ideas which he regarded as erroneous, or 
 even mischievous. He failed to realise how 
 strongly they who believe the whole Bible to be 
 the word of God, and hold its teachings to be the 
 only guide of life, would resent bits of it being 
 used to enforce moral laws of human invention, 
 while the rest of it was ignored or disparaged. 
 
 What he had hoped to be a compromise of 
 peace became, even in his time, and since his 
 death has still more become, like so many other 
 practical compromises, a mother of strife. He 
 did not, even in his last days, repent the com- 
 promise; since through it, it seemed to him, 
 " twenty years of reasonably good primary educa- 
 tion had been secured." But he did not regard it 
 as final. He was forced to admit that the teach- 
 ing of the duties of life according to natural or, 
 as it is sometimes called, secular knowledge, that 
 which he believed to be the true teaching must 
 stand by itself alone and not attempt to make use 
 of any other kind of teaching. It was clear to 
 him that, so soon as it could be brought about, 
 the State must limit itself to teaching the things 
 which belong to natural knowledge and these 
 only, leaving other bodies to teach other things in 
 their own way, offering to all equal opportunities, 
 but meddling with none and directly favouring 
 none. He avowed his conviction that " the prin- 
 ciple of strict secularity in State education is 
 sound and must eventually prevail." 
 
 His zeal for education did not stop, however, at 
 
28 HUXLEY MEMORIAL LECTURES 
 
 children, or at young men and women; early in 
 life he began to put his shoulder to the wheel in 
 the great task of educating the people, of teach- 
 ing the great public of all sorts and conditions, 
 high and low, rich and poor, the main truths which 
 in his opinion ought to guide them in the conduct 
 of life ; and as the years went on the call to fulfil 
 this task seemed to him more and more urgent. 
 He passed from the chair of the professor to the 
 pulpit of the preacher, and in the later years of 
 his life gave himself up almost wholly to the issue 
 of writings which he himself acknowledged to be 
 of the kind which men call sermons. Any 
 attempt to describe Huxley's influence on his 
 fellows and his place in the world which did not 
 give ample room for the consideration of this side 
 of his life and this direction of his labours would 
 be a wholly vain one. 
 
 Following out his favourite analogy of a 
 machine, he recognised in man, on the one hand, 
 a moving power, or rather moving powers, and, on 
 the other hand, directive agencies by which the 
 movements set going by the power, in other 
 words, the acts of man, are shaped so as to accom- 
 plish this and that end. Early in life he had 
 come to the conclusion that these directive agen- 
 cies were to be found in knowledge, in natural 
 knowledge, and in this alone. He was convinced 
 that the true conduct of life was that which was 
 in accordance with the laws of nature, and that a 
 knowledge of those laws could alone supply a 
 
HUXLEY 29 
 
 judgment, the more trustworthy the fuller the 
 knowledge, whether this or that act was in accord 
 with those laws or not, and so whether it was 
 right or wrong. And when he spoke of cc right ' 
 and " wrong," he meant every kind of right, and 
 every kind of wrong. 
 
 His studies in biology had made it clear to him 
 that man must be looked upon as a whole ; that in 
 respect to none of his acts, whatever be their kind, 
 can man's nature be divided into two halves, in 
 such a way that the one half is to be considered 
 as wholly unlike the other half, to be viewed from 
 a wholly different point of view and to be treated 
 in a wholly different way. Without attempting 
 to say what body was or what mind was, he in- 
 sisted that the two were so wed together that no 
 one in dealing with them could put them apart 
 and treat each as if it stood alone. He found it 
 freely admitted that the conduct of man's 
 stomach, however much it had been in earlier 
 times, and indeed still was, governed by the im- 
 pulses of appetite, and by the results of rough 
 experience embodied in custom and authority, 
 was being more and more subjected to rules based 
 on a still imperfect but rapidly growing know- 
 ledge of physiological laws. He noted that 
 whenever any question arose as to what the 
 stomach should be allowed, or be made to do, the 
 final appeal was to physiology, and to this alone, 
 the health and happiness of the stomach being 
 sought for in obedience to physiological laws, and 
 
30 HUXLEY MEMORIAL LECTURES 
 
 in this alone. And what was true for part of man 
 he claimed to be true for the whole of man. 
 Man's whole nature, and not simply this or that 
 part of it, was subject to natural laws; and the 
 welfare of the whole, no less than of each part, 
 was to be sought in obedience to these laws. As 
 the path to so-called physical health lay in the 
 strenuous search after physiological laws, and in 
 obeying them when found, so the path to moral 
 and social health lay in a like search after ethical 
 and social laws and in a like obedience to them 
 when found. He met with no one who contended 
 that because at the present day our knowledge of 
 physiological laws is fragmentary and halting it 
 is to be set aside as of no avail for the conduct of 
 life in its physical aspects; on the contrary, he 
 met everywhere with urgent demands for vigorous 
 research, prompted by the sure conviction that a 
 fuller knowledge would bring to us the means of 
 securing a more wholesome physical life. And 
 he argued that the fact of our knowledge of 
 ethical and social laws being still more fragmen- 
 tary and halting than our knowledge of physio- 
 logical laws so fragmentary and so halting, 
 indeed, that the ethical and social knowledge of 
 to-day might be compared with the physiological 
 knowledge of centuries ago was no valid argu- 
 ment for refusing to accept that knowledge as the 
 ultimate guide in the conduct of life. On the. 
 contrary, it seemed to him that this constituted 
 the very reason why the most strenuous efforts 
 
HUXLEY 31 
 
 should be made to advance that knowledge as 
 rapidly as may be. 
 
 Natural knowledge was, he maintained, the 
 one and the same guide, the only sure guide in 
 the quest after both physical and moral wel- 
 fare. The address " On Improving Natural 
 Knowledge," which was delivered nearly half a 
 century ago, in 1866, and which comes first in the 
 first volume of his collected Addresses and 
 Essays, and is the key to all which follow, sets 
 forth in telling words his conviction that what 
 began as a search into things physical has become 
 a search into things spiritual, and that the value 
 of natural knowledge lies not so much in the 
 mastery which it has given over the forces which 
 determine the welfare of the body (valuable as 
 that mastery may be) as in the mastery which it 
 promises over the forces which determine the wel- 
 fare of man as a whole. Natural knowledge was, 
 he said, " a real mother of mankind, bringing 
 them up with kindness, and, if need be, with stern- 
 ness in the way they should go, and instructing 
 them in all things needed for their welfare." 
 
 The improvement of natural knowledge, whatever direc- 
 tion it has taken and however low the aims of those who 
 may have commenced it, has not only conferred practical 
 benefits on men, but in so doing has effected a revolution 
 in their conceptions of the universe and of themselves, and 
 has profoundly altered their modes of thinking and their 
 views of right and wrong. I say that natural knowledge, 
 seeking to satisfy natural wants, has found the ideas 
 which can alone still spiritual cravings. I say that natural 
 knowledge, in desiring to ascertain the laws of comfort, 
 has been driven to discover those of conduct, and to lay 
 the foundation of a new morality. 
 
32 HUXLEY MEMORIAL LECTURES 
 
 Natural knowledge, moreover, gave man, in 
 his opinion, not only directive agencies, but also 
 moving powers for the conduct of life. It not 
 only laid bare the laws according to which man 
 must walk, but also, rightly grasped, raised up 
 visions which awakened or which strengthened 
 the emotions and affections needed to bear man 
 up in his efforts so to walk, following right and 
 shunning wrong. Love of good, hatred of evil, 
 feelings of awe and reverence, such as must ever 
 arise when man tries to pierce below the surface 
 of things, yearnings for and strivings towards a 
 goal of ideal perfection, nearness to which is the 
 true measure of real happiness these seemed to 
 him the heart of every true religion whatever 
 might be its doctrinal wrappings. Of all these 
 he believed natural knowledge to be, and in the 
 struggles of his own life had found it to be, a 
 true, potent, and yet simple nurse. 
 
 He knew that in this view of the work and 
 power of natural knowledge he was looking 
 ahead ; he was aware how little had as yet been 
 achieved in the improvement of natural know- 
 ledge, how much had yet to be done before that 
 which it promised could be accomplished. But 
 the way to effective truth had been entered upon, 
 time and labour only were needed for the rest. 
 Filled as he was with this dominant conviction of 
 the higher power of natural knowledge and of 
 the crying need for the advance of that know- 
 ledge, it is no wonder that he felt, and felt 
 
HUXLEY 
 
 33 
 
 strongly, that every hindrance of man's own mak- 
 ing to that advance was a hindrance to man's 
 social and moral progress, and told against man's 
 highest welfare. It was this feeling which 
 brought him into conflict with what I may here 
 venture to speak of collectively as the Church. 
 And no true conception of Huxley's life can be 
 gained unless his attitude in this respect be clearly 
 understood. 
 
 He distinguished in the work of the Church 
 between the moving power and the directive 
 agencies. The moving power may be found in 
 the words, love and fear of God, hope and dread 
 of the life to come. The dominant emotion 
 indicated by the words love and fear of God 
 seemed to him, when carefully examined, to be in 
 essence identical with the dominant emotion 
 which he recognised as the moving power making 
 for man's welfare, which had been the moving 
 power of his own life, which had been his religion, 
 and which he spoke of as love of good and of truth 
 and fear of evil and of lies. Whether the good 
 and the true were presented in a personal form, or 
 not so presented, seemed to him to make no real 
 difference in the nature of the emotion itself; and 
 if, on the one hand, it might seem that the 
 emotion was intensified when sustained by a per- 
 sonal conception, on the other hand it might be 
 regarded as more durable and constant when it 
 stood alone and was not in any way contingent on 
 intellectual conceptions. Moreover, so it seemed 
 
34 HUXLEY MEMORIAL LECTURES 
 
 to him at least, as man's knowledge grew more 
 and more, there would come a growing potency 
 of that other accompanying emotion of awe and 
 reverence which springs from the increasing 
 recognition of the mystery of the unknown for 
 ever lying beyond the farthermost margin of the 
 expanding known. 
 
 Towards the other moving power of the 
 Church, the hope and dread of the life to come, 
 his attitude was very different. These words 
 signified, not as did the words love of God, a 
 native emotion shaped, not created, by intel- 
 lectual conceptions, but an adventitious emotion 
 whose very birth was due to conceptions in which 
 natural knowledge was more or less involved. 
 To him natural knowledge brought no proof, and 
 could bring no proof, of a life hereafter; this 
 could neither affirm nor deny that man lived after 
 death. He fully recognised the great part played 
 in the conduct of life by the hope of reward and 
 the dread of punishment; but in the conduct of 
 life according to natural knowledge both the hope 
 and the dread must have natural knowledge as 
 their base; the sequence of the reward or of the 
 punishment upon the deed must be within the 
 reach of proof, otherwise neither the one nor the 
 other could be of avail. The hope and the dread 
 which did not rest on proof seemed to him a 
 broken reed not to be trusted. 
 
 Deep, however, as was his conviction that the 
 hope of future reward and the fear of future 
 
HUXLEY 35 
 
 punishment having no assured basis of certain 
 knowledge, could not be used as the main motive 
 power in the conduct of life without in the end 
 doing harm, strongly as he felt that to go further 
 and put these forward as the necessary and indis- 
 pensable instruments in the moral government of 
 the world was, as he said in a letter to Charles 
 Kingsley, " a mischievous lie," this was not the 
 mainspring of that continued active opposition to 
 the Church which is displayed in so many especi- 
 ally of his later writings. That opposition was 
 engendered not so much by the kind of moving 
 power put forward by the Church as by the direc- 
 tive agencies through which the Church strove to 
 make that moving power effective for the conduct 
 of life. 
 
 He, as I have said, had early come to the con- 
 viction that since the conduct of life, of moral as 
 well as physical life, must be guided by obedi- 
 ence to the laws of nature and by this alone, the 
 welfare of mankind hung upon the continued 
 progress of natural knowledge, through which 
 man learnt the laws which he must obey and saw 
 his way before him. But it seemed to him that 
 the Church in every one of its particular forms, in 
 framing rules for the conduct of life, now to a 
 greater, now to a lesser degree, had made in the 
 past, was making in the present, and would make 
 in the future, use of an appeal to a something 
 which, under the name of authority, inspiration, 
 revelation, was not only no part of natural know- 
 
36 HUXLEY MEMORIAL LECTURES 
 
 ledge, but gave rise to teachings which might be, 
 and often were, in direct contradiction to the 
 teachings of natural knowledge. He further 
 found that when such contradiction came to hand 
 the Church demanded that natural knowledge 
 should give way. This was the origin of the 
 active opposition of which I am speaking. Quite 
 early in his career, while his name was as yet but 
 little known outside the narrow circle of men of 
 science, he was brought face to face with this atti- 
 tude of the Church by the way in which so many 
 voices of the Church received the views put for- 
 ward by Charles Darwin in his Origin of Species. 
 The reception which that book met with entered 
 like iron into Huxley's soul ; he never forgot it. 
 Stirred up by it, he was swept away from the 
 quiet retirement of scientific inquiry, the results 
 of which could not reach the larger world until 
 after many days and then mainly through the 
 mouths of divers interpreters; he was carried 
 forth into the market-place to speak directly to 
 the people and become before them the untiring, 
 fearless champion of the claims of natural know- 
 ledge. It shaped the whole of the rest of his life. 
 Henceforward he to a large extent deserted 
 scientific research and forsook the joys which it 
 might bring to himself, in order that he might 
 secure for others that full freedom of inquiry 
 which is the necessary condition for the advance 
 of natural knowledge. Here was a book which, 
 with a quietness born of the consciousness of 
 
HUXLEY 37 
 
 strength, made known the conclusions to which 
 the author, working wholly within the bounds of 
 natural knowledge, had been led while he during 
 long years patiently gathered observations and as 
 patiently meditated during long years on what 
 those observations meant. Every line in the 
 book dealt with natural knowledge and with 
 natural knowledge alone ; the whole of it appealed 
 to natural knowledge as the only judge of the 
 validity of its conclusions. By the light of 
 natural knowledge Huxley himself tried the 
 book, and, though aware of what was missing in 
 this part or that, accepted the main contention as 
 proved, and in accepting it threw aside views to 
 which at an earlier period he had been led. 
 Others, trying the book also by the light of natural 
 knowledge, found it in their opinion wanting. 
 With these Huxley could not agree; but, though 
 their arguments seemed to him lacking in force, 
 he could not otherwise find fault with their atti- 
 tude. 
 
 With those voices of the Church of which I 
 have spoken, it was different. These, so it 
 seemed to Huxley, rejected the conclusions of the 
 book, not because they were not according to 
 natural knowledge, but because they were, or 
 appeared to be, in contradiction to what was, or 
 what appeared to be, the teaching of the Church. 
 This, he thought, was the real reason of the 
 opposition which so many of the Church offered 
 to Charles Darwin's views ; such opponents might 
 
38 HUXLEY MEMORIAL LECTURES 
 
 arm themselves with arguments drawn from 
 natural knowledge, but the real fight which they 
 were fighting was, in his opinion, one against the 
 validity of natural knowledge itself when in con- 
 flict with the authority of the Church. 
 
 To this conflict Huxley girded himself with all 
 his might on the side of natural knowledge. To 
 understand his attitude it must be remembered 
 how strong, as I have already said, was his con- 
 viction that natural knowledge and natural know- 
 ledge alone is to be trusted as the ultimate guide 
 of man in the conduct of life. The efficacy of 
 the guidance must be measured by the fulness of 
 the knowledge; and Huxley's knowledge was 
 great enough to make him see how imperfect was 
 natural knowledge in its present stage when 
 called upon to rule the conduct of even physical 
 life, and how infinitely more imperfect when 
 appealed to as a guide of the conduct of moral, 
 social life. The welfare of mankind was, in his 
 eyes, indissolubly bound up with the advance, the 
 steady, nay, the rapid advance of natural know- 
 ledge. Any hindrance to that advance was, to 
 his mind, a wrong to mankind. What hindrance 
 could be more hurtful than the contention that 
 natural knowledge was not master of its own 
 domain, but must bow its head and keep silence 
 when even in its own field it came into conflict 
 with the master of another land? The call to 
 strive for the doing away of that hindrance rang 
 loud in Huxley's ears. 
 
HUXLEY 39 
 
 It was in his view of some importance, it was of 
 perhaps of great importance, that Charles Dar- 
 win's conclusions should be generally accepted as 
 solid contributions to natural knowledge, in order 
 to increase their fruitfulness for the further 
 advance of that knowledge; and we to-day can 
 recognise how fruitful they have proved. Still 
 more important was it in his opinion that these 
 conclusions should be judged as to their 
 validity by an appeal to natural knowledge, 
 and to that alone, and not by an appeal 
 to another tribunal. The reception of Charles 
 Darwin's book was to him only an instance, 
 was only one of many signs, of an abid- 
 ing antagonism. The same thing had happened 
 again and again in the past, it must be looked for 
 again and again in the future; the fight will 
 always be going on. His attitude was not 
 changed on hearing other voices of the Church 
 declare that the origin of species, including that 
 of the human species, by selection, was not 
 destructive to the teaching of the Church, but, on 
 the contrary, was in accordance with it, and indeed 
 had in a way been anticipated by it. He was glad 
 that one cause of quarrel was out of the way ; but 
 he felt that even with these voices the potential 
 cause of quarrel still held its ground. They 
 now approved of Darwin's views ; but would they 
 approve of the next great result gained by some 
 student of natural knowledge in even the near 
 future should this seem to them to conflict with 
 
40 HUXLEY MEMORIAL LECTURES 
 
 the teaching of the Church? If they found that 
 it did conflict, would not they also then join in 
 denouncing it? He had no doubt but what they 
 would. He was convinced that the antagonism 
 was a fundamental one. It was one moreover 
 which he seemed to meet with everywhere. 
 
 I had set out [says he] on a journey with no other pur- 
 pose than that of exploring- a certain province of natural 
 knowledge ; I strayed no hair's breadth from the course 
 which it was my right and my duty to pursue ; and yet I 
 found that, whatever route I took, before long I came to 
 a tall and formidable-looking fence. . . . The only alter- 
 natives were either to give up my journey which I was 
 not minded to do or to break the fence down and go 
 through it.* 
 
 And especially during the latter years of his life 
 he set himself vigorously to the task of breaking 
 down fences. 
 
 The Church, he said to himself, whenever it 
 sees fit, opposes natural knowledge; in the ser- 
 vice of my sovereign lord, natural knowledge, it 
 is my duty to oppose the Church. I am not going 
 out of my way in doing this ; it lies straight before 
 me in my path. He went on the way which he 
 had set before him, well knowing that in so doing 
 he gave great offence. To many a quiet Christian 
 heart he brought much pain, handling, as he did, 
 themes which to them were indissolubly joined to 
 their inmost feelings of reverence, with the free 
 manner of a fighter who flashes in his sword 
 wherever he sees an opening to do his 
 
 * Collected Essays, V., Pref. p. vii. 
 
HUXLEY 41 
 
 opponent harm. To those who blame him for 
 this the reply may be given that the greater the 
 reverence resting on what he was convinced was 
 a false foundation, the more pressing seemed to 
 him the duty to show the falseness of the founda- 
 tion in the clearest, most direct way, such as could 
 be understood by all. Moreover, the manner in 
 which he used his weapons in this matter was in 
 no wise different from his usual manner on other 
 occasions. He was by temperament " ever a 
 fighter " ; in his combats within the realms of 
 natural knowledge, and these were not a few, he 
 hit quick and he hit hard, for such was his way of 
 fighting. 
 
 Many of his friends, who, like him, put their 
 trust in natural knowledge, reproached him with 
 spending his strength in warfare of such a kind. 
 The surest way to make natural knowledge pre- 
 vail, they said, is to extend its boundaries; as it 
 advances other things must give way before it. 
 Was it not a misdirection of energy that he who 
 in past years had shown such power and done so 
 much to drive farther and farther off the line 
 which parts the known from the unknown, should 
 spend time and labour in controversies which in 
 themselves brought no clear advancement of 
 natural knowledge, and in conducting which he 
 could make little use of that wealth of natural 
 knowledge which he already possessed, and had, 
 with tireless labour, to seek the arguments which 
 he used in unaccustomed antiquarian and lingu- 
 istic studies ? 
 
42 HUXLEY MEMORIAL LECTURES 
 
 He thought otherwise. He was convinced, and 
 increasingly convinced as years went on, that 
 natural knowledge could not go on to that fuller 
 development which was needed to make it 
 accepted as the true guide in the whole conduct 
 of life, so long as men in general still believed 
 that as regards parts of that conduct the only true 
 guide was to be found in the teachings of the 
 Church and in these alone. He had no doubt 
 whatever that for the adequate progress of natural 
 knowledge some one must be bold enough to 
 stand up against the Church whenever it said to 
 natural knowledge, " thus far but no farther," 
 bold enough to show the world that the Church's 
 claim to dictate to natural knowledge broke down 
 when it was tried without fear and without preju- 
 dice. Seeing none other bold enough, he took 
 the task upon himself. Whether he was right or 
 wrong, the world must judge. 
 
 He is gone; but the conflict, in which so much 
 of his life was spent, still remains with us. 
 Among the followers of natural knowledge, both 
 the workers and they who only know its ways, 
 there are and always will be they who hold that 
 natural knowledge is not merely a hewer of wood 
 and a drawer of water, a provider of physical 
 health and material benefits, but beyond that the 
 only sure guide to moral health and spiritual well- 
 being, who hold that man can only safely direct 
 his steps by frank obedience to the known laws of 
 nature, the more safely the better and the more 
 
HUXLEY 43 
 
 fully these laws are known. Such are well aware 
 that the always increasing, but ever limited 
 known is wrapped round on all sides with a 
 boundless unknown. Peering from time to time 
 into that dark unknown they may people its 
 depths with fancies ; but they leave those fancies 
 there when they turn back to their daily task in 
 the clear light of the known. Yet the feelings of 
 wonder and awe with which that vast unknown 
 must always fill them will abide with them, 
 chastening and humbling them, ennobling their 
 daily task and fitting them the better to perform 
 it. Borne up by such feelings Huxley lived and 
 worked. 
 
 MICHAEL FOSTER. 
 
45 
 
 *HUXLEY AND NATURAL SELECTION 
 By Prof. E. B. Poulton, F.R.S. 
 
 On March 23, Prof. E. B. Poulton, F.R.S., 
 delivered the Huxley Lecture at Birmingham. 
 He said the attitude of Huxley toward natural 
 selection was remarkable and unusual. Although 
 no one fought so nobly, and against such odds in 
 its favour, although no one had ever fought the 
 battle of science with such success, [Huxley was 
 never a convinced believer in the theory he de- 
 fended from unfair attack.^ At least one cause of 
 that want of confidence he (the lecturer) believed 
 to be due to the fact that his researches, deter- 
 mined by the bent of nature, were anatomical and 
 palseontological rather than the study of the 
 living organism in relation to its environment, 
 and especially its living environment. The 
 origin and growth of the theory and the circum- 
 stances under which it was made public had often 
 been told. Darwin, convinced of evolution by 
 reflection upon his observations in South America 
 during the voyage of the "Beagle" (1831-36), 
 began in July, 1837, systematically to collect 
 facts bearing upon the modification of species and 
 its causes. In October of the following year he 
 read Malthus " On Population," and the idea of 
 natural selection at once dawned on his mind. 
 
 * 'Revised from the ^Scientific American" Supplement, Vol. 59, 
 
 p. 24515-16, April IQOS. 
 In full in " Essays on Evolution," Oxford, 1858, pp. 193-219. 
 
46 HUXLEY MEMORIAL LECTURES 
 
 In June, 1842, he wrote a brief account of the 
 theory, and two years later an essay; but he could 
 not be induced to publish until, on June 18, 1858, 
 almost exactly twenty years after the conception 
 first came to him, he received a manuscript essay 
 written by A. R. Wallace in the Moluccas " On 
 the Tendency of Varieties to Depart Indefinitely 
 from the Original Type." Darwin placed him- 
 self in the hands of his friends Lyell and Hooker, 
 who asked for an abstract of his own work, and 
 presented it, with Wallace's essay, to the Linnean 
 Society on July i, 1858. Now that we knew the 
 circumstances under which Wallace wrote his 
 essay, the coincidence was far more striking. He 
 also was convinced of evolution, and had written 
 a powerful paper in support of it. But he knew 
 of no motive cause until, in February, 1858, lying 
 ill of fever in Ternate, he began to think of 
 Malthus's book, and the idea of natural selection 
 instantly flashed across his mind He did not 
 wait twenty years. In two hours he had thought 
 out almost the whole of the theory, in three even- 
 ings he had finished it, and sent it to Darwin. 
 Thus on July i, 1858, when Darwin was nearly 
 fifty and Huxley just over thirty-three, the great 
 theory was before the world, and the most striking 
 thing about Huxley in relation to it was the fact 
 that he knew nothing about it. Almost exactly 
 a year after the appearance of the paper, on June 
 25, 1859, he wrote to Lyell in favour of the trans- 
 mutation of species, but against the idea of 
 
NATURAL SELECTION 47 
 
 transition between species. The letter showed 
 that he had no notion of natural selection, but 
 only of changes wrought by external conditions, 
 changes sudden and sharply marked off, like those 
 which follow the replacement of one chemical 
 element by another in a compound to use his 
 own metaphor. ' The Origin of Species " was 
 published in November, 1859, and an advance 
 copy was sent by Darwin to Huxley. In his 
 chapter on the reception of " The Origin of 
 Species " (" Life and Letters of Charles Darwin," 
 Vol. II) Huxley said : " My reflections when I 
 first made myself master of the central idea of 
 the ' Origin ' was how extremely stupid not to 
 have thought of that " further evidence that he 
 had known nothing of the details of the Linnean 
 Society paper, where the central idea was admir- 
 ably, although, of course, briefly, explained by its 
 discoverers. 
 
 Huxley's want of knowledge of natural selec- 
 tion in the interval between July i, 1858, and the 
 end of November, 1859, suggested several inter- 
 esting reflections. Great and original workers 
 rarely had the time for wide reading in their sub- 
 ject away from the lines of their special investiga- 
 tions. They were also held back by the feeling 
 that the attempt to be encyclopaedic was itself 
 destructive of originality ; and yet there was noth- 
 ing so inspiring to a young worker as the fact that 
 his attempts had interested a great and original 
 leader in his own subject. The position looked 
 
48 HUXLEY MEMORIAL LECTURES 
 
 like a dilemma, but the escape was easy. The 
 conditions of science were daily becoming more 
 favourable at our Universities, where the older 
 worker had a parental interest in the younger 
 and would by no means quench the smoking flax 
 by unintended neglect. Science was also rich in 
 societies where old and young could meet, and 
 where through personal contact, far better than 
 by endless hours of reading, the deepest inspira- 
 tion and the highest encouragement could be 
 given and received. 
 
 If, however, the antagonism between the 
 excessive cultivation of the memory and the 
 development of originality was seen in the 
 lives of older men, whose capacity for the 
 highest work was proved and certain, surely 
 conclusions of value were to be learned from 
 those whose duty it was to watch over the 
 developing mind of the young. A little know- 
 ledge was said to be a dangerous thing; but as 
 regarded the awakening and growth of the most 
 indispensable part of our intellectual equipment 
 the imagination it might be more truly said 
 that a great deal of knowledge was a dangerous 
 thing. With the very best intentions, but with 
 the very worst results, the idea had taken root in 
 this country that the imagination must not be 
 allowed free play until some arbitrary amount of 
 knowledge had been imbibed, and the result was 
 that too often all original faculty was waterlogged 
 and drowned in a sea of facts. 
 
NATURAL SELECTION 49 
 
 Huxley's independent views on evolution 
 were what we should expect from a great 
 student of animal structure rather than of animal 
 life, who was at the same time a profound and 
 cautious thinker. Huxley told us that before 
 the appearance of the " Origin " he took his stand 
 upon two grounds first, that up to that time the 
 evidence in favour of transmutation was wholly 
 insufficient; and, secondly, that no suggestion re- 
 specting the causes of the transmutation which 
 had been made was in any way adequate to ex- 
 plain the phenomena. And yet all along there 
 was alive in him a sort of pious conviction that 
 evolution would turn out true, and the kind of 
 evolution he imagined was, so far as we were able 
 to judge, a conception which would arise in the 
 mind of one who compared animal structures with 
 the eye and brain of the artist or engineer rather 
 than of the naturalist. At the age of twenty-six he 
 wrote to W. S. Macleay ; " I am every day be- 
 coming more and more certain that you were on 
 the right track thirty years ago in your views of 
 the order and symmetry to be traced in the true 
 natural system." Macleay's ideas of the grouping 
 of the animal kingdom were about as regular and 
 symmetrical as the figures seen in a kaleidoscope. 
 And a conception of sharply separated mathe- 
 matically grouped forms would naturally lead to 
 the idea of evolution by sharp and abrupt steps, 
 whereby a new form would appear by sudden 
 transformation of the old, just as a chemical com- 
 
50 HUXLEY MEMORIAL LECTURES 
 
 pound changed when one element in it was re- 
 placed by another. 
 
 The evidence at our disposal led to the belief 
 that such was the state of Huxley's mind when, in 
 November, 1859, he read the " Origin." He there 
 met with far more convincing proofs of evolution 
 than he had ever encountered before, and he 
 accepted them at once, unreservedly, permanently. 
 He furthermore encountered what was to him the 
 entirely new idea of natural selection, and he 
 recognised that it disposed of his earlier objection 
 that no motive cause in any way adequate had 
 been suggested. But to the end of his life he 
 never went beyond that. He never committed 
 himself to a full belief in natural selection, and 
 even contemplated the possibility of its ultimate 
 disappearance. The difficulty which he felt 
 early and late, and about which he had a pro- 
 longed discussion with Darwin, was the fact that 
 the breeds created by the artificial selection of 
 man were mutually fertile, while the species 
 created ex hypotkesi by natural selection were 
 mutually sterile. Without going into the contro- 
 versy, it might be said that, according to Darwin, 
 Huxley's objection merely meant that the results 
 of an experiment prolonged for an immense 
 period were not in every respect the same as those 
 attained when it endured for a time compara- 
 tively brief. Students of living* nature felt a 
 confidence in natural selection which was not 
 shared by this great leader. Just as it required 
 the naturalist to discover the principle itself, so 
 
NATURAL SELECTION 51 
 
 the experience which brought belief in it was that 
 mainly of the naturalist, and the strongest con- 
 fidence in the abiding truth of a theory was gained 
 by those whose imagination had been inspired by 
 it. Every verified prediction made by the light 
 of natural selection placed the theory upon a more 
 secure foundation. That foundation had been 
 growing more secure for nearly half a century; 
 but, as Prof. Poulton showed in conclusion, that 
 increasing confidence was not so much due to the 
 facts which were the province of the anatomist as 
 those which formed the every-day experience of 
 the naturalist, of the man who studied animal 
 form and change and instinct, not in relation to 
 the single individual or the single species, but in 
 relation to the whole environment, and especially 
 the living environment. That kind of study did 
 not appeal to Huxley's nature, and therefore the 
 confidence in natural selection, of which the lec- 
 turer had spoken, was not for him ; but those who 
 felt it should never forget how much they owed 
 to Huxley for the leading part he took in the great 
 battles which had to be fought before evolution 
 and natural selection were accorded a fair hear- 
 ing ; and his success went far beyond even those 
 issues. Whatever stirring and subversive ideas 
 the future might be preparing for us, we might be 
 sure that they would never suffer from the treat- 
 ment accorded to the " Origin of Species," and 
 far more than to any other single man the world 
 owed that immense gain to Thomas Henry 
 Huxley. 
 
53 
 
 RATIONALISM AND SCIENCE IN 
 RELATION TO SOCIAL MOVEMENTS. 
 
 By Prof. Percy Gardner. 
 
 Whether your Council have made a mistake in 
 the selection of the present Huxley lecturer it will 
 be for my audience to judge. But up to a certain 
 point I think they were certainly right. They 
 decided that when a lecture was founded to com- 
 memorate a man so many sided as Thomas 
 Huxley, justice could not be done to him if only 
 a succession of biologists were nominated to the 
 lectureship. I am older than most of my audi- 
 tors, and vividly remember the part which Huxley 
 played in the national life. He was not merely 
 an authority on biologic questions, a first-rate 
 lecturer on science and a prominent champion of 
 Darwinism, but also a man through whose clear 
 and powerful brain all the great questions of our 
 time circulated, finding there an alembic whence 
 they often issued altered and clarified. He was 
 not only a man of science but also a man of 
 letters, a philosopher, even in a degree a theo- 
 logian. He once said of Mr. Arthur Balfour 
 that he had science in his blood; we may say of 
 Huxley that he had literature in his blood. If 
 
54 HUXLEY MEMORIAL LECTURES 
 
 we accept Matthew Arnold^s_ view jhajL-the.- pur- 
 suit of letters consists in the acquainting oneself 
 with the best which has been thought and said in 
 the world, Huxley was literary; if we accept the 
 same writer's definition of religion that it is 
 morality heightened, kindled, lit up by feeling, 
 Huxley was religious. And it was the combina- 
 tion in him of science with literature and religion 
 which made him so great a force in the England 
 of the Victorian age. 
 
 I never had the honour of personal contact with 
 Huxley, but I heard him speak more than once, 
 and his writings have deeply interested me since 
 I was a child. I owe him a debt, which I may 
 best pay by trying to combine as he did the 
 fanaticism of veracity which marks the man of 
 science with the broad outlook on human life 
 which belongs to the man of letters. But the last 
 quarter of a century has been a time of rapid, of 
 constantly accelerated, intellectual movement, 
 and Huxley, who was himself ever on the crest of 
 the advancing wave, would condemn me if I did 
 not try to penetrate further than he did into some 
 of the tendencies of thought which are ever ebb- 
 ing and flowing, and are now more clearly to be 
 discerned than they were twenty years ago. 
 
 I. 
 
 I have taken as my subject Rationalism and 
 Science, in relation to social movements, and I 
 must begin by trying to explain in what sense I 
 
RATIONALISM AND SCIENCE 55 
 
 use these words. We are used to the word 
 rationalism in religious discussions, and there we 
 attach to it, as does Lecky in his History of 
 Rationalism, a somewhat negative meaning. We 
 think it implies the denial of old-fashioned ortho- 
 doxy, and greater reliance on reason and common 
 sense. I do not propose to use the word in this 
 somewhat narrow acceptation. Again, the word 
 science is in this country applied almost exclu- 
 sively to the knowledge of the phenomena of the 
 material world, physics, chemistry, biology. But 
 this is an abusive use of the term. For science 
 can be nothing but orderly knowledge, and 
 orderly knowledge is just as possible in such 
 studies as philology and archaeology and history 
 as in those dealing with the physical world. In 
 all the great academies of Europe it is fully recog- 
 nised that science has two great branches, one of 
 which deals with the visible world, the other with 
 man, his faculties and his history. 
 
 The question which I propose to discuss is the 
 parts belonging respectively to rationalism and 
 to science in modern civilisation and progress. 
 And I beg to be allowed to mean by rationalism 
 the adoption of certain fixed principles from which 
 the course of our action may be deduced or argued 
 out; and by science I would mean the regular 
 and methodic knowledge of man, in the past and 
 the present ; the investigation not of ethical prin- 
 ciples but of consequences, of events, and of the 
 results of action. But I must explain. 
 
56 HUXLEY MEMORIAL LECTURES 
 
 Human progress in general, the passage of 
 mankind from a lower to a higher level, consists, 
 as I earnestly believe, and as I have tried to shew 
 elsewhere, in the gradual embodiment in society 
 of certain impulses and tendencies arising in the 
 obscure regions of sub-conscious life, and gradu- 
 ally making their way into all the forms of human 
 activity, thought, feeling, action, art, institutions 
 and social organization. These creative and life- 
 giving impulses I should prefer to call divine 
 ideas; but if anyone regards this phrase as too 
 theological and question-begging, I will not at 
 this moment insist upon it. We need not stay to 
 examine the origin of these ideas ; we have enough 
 to do in tracing their manifestation in the field of 
 consciousness. However they originate, they 
 come bubbling up from unknown depths like the 
 springs of rivers among the hills, and pass on to 
 make the fields of life fertile. To each genera- 
 tion and to every nation it is given, or at least 
 the opportunity is given, to manifest some par- 
 ticular ideas in higher or completer form. The 
 Jews owe their place in the history of the world to 
 their enthusiasm for the idea of the divine guid- 
 ance and government of mankind, the Romans 
 to their sense of civic law and order. The 
 Greeks, more susceptible to ideas than any race 
 that ever lived, have left us imperishable embodi- 
 ments of the ideas of rationality, of human beauty, 
 of measure and method in all things. The best 
 achievement of the Teutonic races was their 
 
RATIONALISM AND SCIENCE 57 
 
 development of the ideas of loyalty and chivalry. 
 These races, and indeed all great races, have 
 added some adornment to the temple of humanity, 
 and made the life of each succeeding generation 
 a thing of higher and nobler possibilities. No 
 doubt they have all had defects to balance the 
 excellences, the Jews narrowness and fanaticism, 
 the Romans hardness and cruelty, the Greeks 
 frivolity and want of moral purpose, the Teutons 
 the vices of an aristocracy. But to every man 
 whose eyes are not jaundiced by cynicism, these 
 great national inspirations, in spite of all draw- 
 backs, will appear as the rich legacies of the past, 
 making life in the present worth living. 
 
 Savages and barbarians below a certain stage 
 of development have attained a definite organiza- 
 tion, what may be termed an equilibrium. They 
 often go on from century to century without any 
 great change. It is the rise of ideas which breaks 
 the crust of fixed custom. The innovators are 
 commonly regarded as destructive and mis- 
 chievous, so that the path of progress is strewn 
 with the bones of martyrs. It is through the self- 
 devotion of the few that the many climb painfully 
 to a higher level. 
 
 The ideas as they rise from the unseen depths 
 of consciousness usually first make themselves 
 known in action. They affect will and emotion, 
 which are nearer akin to the unconscious, before 
 they seek justification in thought. But sooner 
 or later the rational part of man must be satisfied 
 
58 HUXLEY MEMORIAL LECTURES 
 
 as well as his emotional part. He has to give 
 some sort of reason for the hope that is in him. 
 
 History shews us very clearly how this demand 
 for a reason is at first met among all peoples and 
 nations. It is met by a direct claim that the line 
 of advance is shewn by revelation, that some per- 
 son or society is inspired by the gods to lead the 
 people in the right way. We are familiar with 
 this kind of appeal from our acquaintance with 
 the Old Testament. Nowhere is it so clearly 
 and emphatically set forth as in the Jewish 
 Scriptures, and quite especially in the writings of 
 the earliest of the great prophets, A^mos and 
 Hosea. It is the word of the Lord which they 
 make known to the people; and they tell their 
 contemporaries in burning sentences that it is their 
 life and peace to hear that word and to do it. 
 But our religious horizon has greatly widened of 
 late years, and we now know that among all 
 peoples such a claim has been put forth by 
 prophets. Israel is the prophet among the 
 nations; but all nations have received from time 
 to time like prophetic commands. The king of 
 Assyria did not march to subdue the nations save 
 at the command of Asshur. Numa received the 
 laws of Rome from the goddess Egeria. 
 Pharaoh of Egypt was an impersonation of the 
 Sun-god Ra. Pythagoras was an inspired 
 prophet, and his society arose on a theocratic 
 basis. Nor was this claim at all confined to the 
 men of the childhood of the world. Socrates was 
 
RATIONALISM AND SCIENCE 59 
 
 launched on his career by the voice of the Apollo 
 of Delphi. And through all the Middle Ages, 
 the great Reformers and the Founders of Monas- 
 tic Societies were fully convinced that they had 
 a special mandate from above, which they dared 
 not disobey. I need mention but three of the 
 most conspicuous names, St. Francis, Luther, 
 Wesley, all of whom were consciously the 
 vehicles of a divine command. 
 
 This answer to the demands of the human intel- 
 lect, the direct appeal to a divine inspiration, can- 
 not be called a form of rationalism. What we 
 know as rationalism is rather the very opposite. 
 Rationalism arises as the belief in direct inspira- 
 tion grows weaker. It is a reply to scepticism. 
 When a prophet is asked by what authority he 
 commands, he answers by a manifestation of 
 spiritual force. But this reply does not satisfy 
 the doubters of a sceptical age. 
 
 I am speaking, it must be remembered, of great 
 ethical movements, proposals that we should 
 modify our way of conduct, in regard to some of 
 the great and important matters of life. A 
 movement in such and such a direction, we sup- 
 pose, is springing up in the consciousness of men. 
 It will scarcely in our days be accepted on the 
 authority of a prophet claiming a direct mandate 
 from heaven. It meets with enthusiastic appro- 
 bation and with determined opposition. We have 
 as best we may to reason out its goodness or bad- 
 ness in discussion. This may be done either in 
 
6o HUXLEY MEMORIAL LECTURES 
 
 the way of rational ethics or of science. The 
 ethical way is to make appeal to some principle 
 generally accepted in the society, rights generally 
 recognized, beliefs which are not seriously ques- 
 tioned. It has to be shewn that the proposed 
 change is in accord with or contrary to these, so 
 that consistency would compel us in the one case 
 to accept, in the other to reject it. The way of 
 science is to shew the results which follow the 
 adoption of the disputed principle, results either 
 good or bad, either attracting us towards it, or 
 warning us to avoid it, as we avoid disease and 
 death. 
 
 But abstract talk like this tends to make the 
 ears dull, so that the speaker does not take his 
 audience with him. Rather let us take a con- 
 crete case, in order that we may see the two 
 methods of which I am speaking not as mere pos- 
 sibilities but as actually working principles. We 
 will take up a controversy now practically ex- 
 tinguished, but raging with great force in the last 
 century, the controversy which ended in the 
 abolition of negro slavery in the British Colonies 
 and in America. 
 
 Here the ultimate spring was no doubt an 
 impulse springing up in the consciences of thou- 
 sands a conviction of the sinfulness of slavery. 
 When the matter had to be argued on the plat- 
 form and in the legislatures, the impulse had to 
 be put on terms with men's ordinary ways of 
 thinking and action. The advocates of emanci- 
 
RATIONALISM AND SCIENCE 61 
 
 pation sometimes appealed to the general belief 
 in certain rights of man, the principle that a being 
 having human form and human faculties had also 
 certain inherent rights, or the thesis that God had 
 made all men of one blood. This may be re- 
 garded as the rationalist side of their appeal : 
 but they also had resort to arguments of another 
 kind, which were more closely akin to the demon- 
 strations of science. They tried to shew that 
 slavery had in the past worked with pernicious 
 effect on the societies which had adopted it, and 
 was in the countries which upheld it even in our 
 own time working great harm on the character 
 alike of the slave-holder and the slave. Some- 
 times they would take a lower line, and try to shew 
 that in production slave labour was actually less 
 efficient than free labour, and so dearer. 
 
 The controversy in regard to slavery may be 
 said to be now closed. And we are disposed to 
 think that the arguments were all on one side. 
 But a century ago, there were good and wise men 
 who took another view; and they also appealed 
 alike to accepted principles and to history and 
 experience, especially the latter. 
 
 Thus the abolitional movement found means 
 for capturing the three great parts of human 
 nature, will, emotion and intellect. The inner 
 impulse bent the wills of men, especially carrying 
 away in a strong enthusiasm the wills of the 
 leaders of the movement, Wilberforce, Clarkson 
 and the rest. The ethical appeal told especially 
 
62 HUXLEY MEMORIAL LECTURES 
 
 on the contagious enthusiasms of the platform; 
 and in these days of popular government, argu- 
 ments suited to the orator are necessary in all 
 matters involving legislation. The appeal of 
 science acted on more thoughtful people, com- 
 paratively few in number, but having influence 
 out of proportion to that fewness, in virtue of their 
 intelligence, and the quiet steadiness of their con- 
 victions. The final result was a great effort of 
 national will, but it was helped on, and even made 
 possible, because emotion and intellect worked 
 on the same side. 
 
 But now we come to other forces which are 
 mainly beyond human control, the constitution of 
 man and the human environment. Let us sup- 
 pose that there were two states existing side by 
 side; and that in one of these negro slavery was 
 abolished, while in the other it was retained. The 
 two would necessarily compete, and one would be 
 found more efficient, more successful than the 
 other. Evidently here the abolitional idea would 
 have to undergo a fresh test, that of working. 
 And apart from violent interference of one state 
 with the other, which is of course what happened 
 in the United States, the final triumph of the one 
 polity or the other must be determined by fact 
 and by event. If the idea of abolition was in 
 harmony with the facts of human nature, it would 
 triumph. But if the impulse from which it arose 
 was a baseless sentiment, if the natural rights of 
 man were a delusion, and if the men of science 
 
RATIONALISM AND SCIENCE 63 
 
 misjudged the results of slavery, then the slave- 
 state would in the course of time crush out the 
 state which abolished slavery, and survive. 
 
 There is then an ultimate test to which all 
 human endeavours, all plans and all institutions 
 must submit, the test of working, of fruits, of sur- 
 vival. It is a hard test, proceeding without fear 
 or favour, and ruthlessly trampling out whatever 
 will not endure it. This is of course no new 
 doctrine; and from the beginning of literature it 
 has been expressed in a hundred ways. The 
 Hebrew Psalmist wrote ' Such as be blessed of 
 the Lord shall inherit the earth, and they that be 
 cursed of him shall be cut off.' ' What is con- 
 trary to nature cannot succeed ' is the burden of 
 philosophy in all ages, and especially of the 
 greatest of all practical philosophies, the Stoic. 
 And when in the last century Darwin emphasized 
 the principle of the survival of the fittest, it was 
 but this old wisdom made new. 
 
 The law of the survival of the fit and the 
 destruction of the unfit works in the whole field 
 of biology. And it works in human society. 
 But it does not work among men with the same 
 force and regularity with which it works among 
 plants and animals. For the free will of man, 
 however it be explained, is an existing reality : 
 and man has the power of modifying his sur- 
 roundings, even in some cases of dominating 
 them. When two states compete in the markets 
 of the world, that in which the labour is most efn- 
 
64 HUXLEY MEMORIAL LECTURES 
 
 cient will tend to drive out the other. But the 
 state of less efficient labour may be stronger as a 
 military force, and throw the sword into the scale, 
 or it may be wiser politically and make treaties 
 which shall give it an advantage in the markets. 
 Or it may by higher internal organization diminish 
 the friction which wastes power, and so make up 
 for inferior powers of production. And within a 
 state persons or classes of persons who would in 
 the natural course of things be starved on account 
 of their inefficiency may be kept alive through 
 feelings of humanity. And education regulated 
 by the state may be shaped for the particular pur- 
 pose of promoting the efficiency which leads to 
 survival. 
 
 In speaking of the conditions and environment 
 of life it must not be supposed that I speak as a 
 materialist, and am thinking only of the natural 
 frame in which our lives are set. I believe fully 
 that we also live in a spiritual environment, that 
 our lives are parts of a greater and universal life, 
 that we belong to a great commonwealth of spirit. 
 And further I believe that in this spiritual world 
 there may be traced something akin to human 
 will and purpose, but on a higher scale. The 
 ultimate fact for us is not the material world, but 
 the spiritual power which dwells in it and has 
 created it. But this spiritual world also has its 
 laws, not fixed and rigid like the course of the 
 stars, but yet overpowering and dominant. 
 
 Our environment may best be regarded as a 
 
RATIONALISM AND SCIENCE 65 
 
 stream of tendency which bears us all along. If 
 we are passive we move on steadily. If we 
 resist, we may swim against the stream, but it is 
 difficult and a constant drain of energy. If we 
 swim with the stream we move fast. It is by 
 swimming against the stream, very often, that 
 character and personality are made. But our 
 lives are short; and in the long run the stream 
 has its way with communities if not with indi- 
 viduals. Our efficiency, and especially our effi- 
 ciency in societies, depends greatly on going 
 rather with than against the current. 
 
 It was necessary thus to map out the ground, in 
 order to lead up to the things on which I really 
 want to insist. The corollaries which follow the 
 truths which I have outlined are not regarded as 
 truisms. And it seems to me of great importance 
 that they should be brought forward on occasions 
 like the present, when a broad outlook on the 
 great problems of life is specially in place. Pro- 
 gress, I have maintained, consists in the absorp- 
 tion into the frame of society of practical impulses 
 or ideas. These ideas must be justified by 
 appeals to accepted principles and to experience. 
 And it is of the utmost importance that the ideas 
 themselves should be in harmony with the laws 
 of human nature, and that their working in the 
 world should be seen as it really is. In all these 
 respects in our days great difficulties arise from 
 the character of our civilization and the existing 
 habits of thought. 
 
66 HUXLEY MEMORIAL LECTURES 
 
 It is clear that the intellectual presentation of 
 the ideas requires three classes of workers. We 
 need a class of prophets who shall be susceptible 
 to the ideas as they slowly emerge from the 
 ground of the unconscious. We need phil- 
 osophers and men of letters to connect them with 
 the principles generally accepted by society. 
 And we need men of science and observation, to 
 trace the results of their working in history and 
 in the human world around. 
 
 After all the great task is to persuade the 
 people. In our days, whether for good or for 
 evil, whether we like it or not, democracy has be- 
 come more and more the ruling power. Even a 
 Caesar cannot move in any direction against the 
 grain of his people's will. Nor can an aristocracy 
 retain the direction of affairs, unless it can per- 
 suade the many that it rules for the general good. 
 The counting of heads to save, as Bentham said, 
 the trouble of breaking them, is the final test in 
 all practical matters. This being a fixed point, 
 let us consider how the working of ideas, which is 
 to the community what the circulation of the 
 blood is to an individual body, finds course or 
 hindrance among us. 
 
 We need not greatly concern ourselves about 
 the prophets. They are, so to speak, the super- 
 natural element. Their advent cannot be pro- 
 cured or foretold any more than can the weather 
 of a week hence. There will always be prophets, 
 some true and some false, claiming to be heard : 
 
RATIONALISM AND SCIENCE 67 
 
 the great need of mankind is to discern between 
 those who lead to what is good, and those who 
 seduce to what is evil. The really practical 
 questions have to do with the tests by which ideas 
 are to be tried. 
 
 In such testing it seems to me that, ever since 
 Darwin and his school came upon the stage, the 
 appeal to fact, to experience, to results has been 
 steadily gaining in efficacy, at the expense of 
 what may be called the rationalist appeal to a 
 priori principles and beliefs. The reason is not 
 far to seek. The constantly growing restlessness 
 of mankind, the changes in our surroundings both 
 social and economic, the drain of those who lived 
 in the country towards the great cities with their 
 life of fevered activity, have made it hard for any 
 accepted principles to hold their place. The 
 tendency is to call in question all the beliefs 
 whereby in times past men have directed their 
 actions. And on the other hand, science, which 
 is of course only organized and formulated obser- 
 vation and experience, has been maturing with a 
 rapidity compared with which its previous pro- 
 gress was but slow even in the most active and 
 intellectual ages of the world's history, the ages 
 of Aristotle and of Leibnitz. Into every branch 
 of knowledge we are introducing method ; the pro- 
 gress of discovery is advancing into fields never 
 yet occupied; the test of results is the one test 
 which is always accepted. 
 
 I am not concerned to justify this progressive 
 
68 HUXLEY MEMORIAL LECTURES 
 
 supersession of rationalism by science. In many 
 ways it is to be deplored. The restlessness of 
 modern society is in itself a serious evil ; and one 
 looks with anxiety to see whether the great root 
 principles which have been worked into the fabric 
 of modern society will not be called in question. 
 Even such institutions as monogamy and the pos- 
 session of private property do not pass without 
 inquiry. All this, one hopes, is transitional, the 
 result of too rapid changes physical and social. 
 But whether one deplores, or whether one de- 
 fends, the change in the centre of gravity, that 
 such a change is taking place is past question. 
 A recent speaker in the House of Commons spoke 
 of the doctrine of the rights of man as ' dead as 
 Rousseau ' : and one could scarcely contradict 
 him. 
 
 And looking in all directions for a remedy, one 
 can find it only in a broader, more human, more 
 profound, study of human phenomena, and the 
 growth of a science treating of man and his facul- 
 ties as well developed and as detailed as is the 
 study of the visible universe. No such science 
 can give us ideals; there can be no mere obser- 
 vational determination of right and wrong, good 
 and evil ; but still, fuller knowledge may serve to 
 protect us against some of the aberrations and 
 absurdities which threaten society. 
 
 I have been reading the recently published 
 letters of a man for whom I have always had the 
 deepest respect, John Stuart Mill. Those letters 
 
RATIONALISM AND SCIENCE 69 
 
 are full of the intellectual honesty and moral 
 courage in which Mill perhaps surpassed all his 
 contemporaries. But they are instructive in 
 another way. Mill's career immediately pre- 
 ceded the great trend in the direction of the 
 scientific treatment of human problems which we 
 owe mainly to the influence of Darwin and 
 Spencer. His letters remarkably illustrate the 
 distinction which I have drawn between the 
 rationalist and the scientific way of considering 
 problems of conduct and sociology. The 
 rationalist is self-confident, fully trusting in argu- 
 ment, ready to assert his principles in season and 
 out of season. The man of science is, or ought 
 to be, modest, laborious, most anxious to omit no 
 phenomena, having a deep respect for every view 
 which has actually worked among men. A letter 
 of Mill's in regard to the religious observance of 
 Sunday is very typical.* One would expect the 
 great advocate of Utilitarian Ethics, before con- 
 demning this institution, to consider what part it 
 had played in the history of England and Scot- 
 land, and what practical results might follow from 
 its destruction. But the rationalist in Mill is far 
 too strong for any such investigation. To attri- 
 bute any sacredness to the day, he writes, ' is as 
 mere a superstition as any of the analogous pre- 
 judices which existed in times antecedent to 
 Christianity.' The preservation of the Sunday 
 
 * Letters, I, 100. 
 
70 HUXLEY MEMORIAL LECTURES 
 
 as a day of devotion is, according to the writer, 
 mere cant. ' The devotion which is not felt 
 equally at all times does not deserve the name/ 
 And so he proceeds. It is strange that it did not 
 occur to him to consider why in such a case the 
 observance of Sunday had so long persisted in 
 Great Britain. In some of Mill's letters one finds 
 a painful consummation to which such rationalism 
 as his may easily lead. He expresses a deliberate 
 opinion that in the government of the world the 
 spiritual power of evil is stronger than the power 
 of good. That, I think, is a conclusion which 
 will often be reached by a rationalist who first 
 determines by the light of his own sentiments 
 what a moral government of the world ought to 
 be, and then condemns that which actually exists 
 because it does not conform to such preconceived 
 notions. The spirit of science is utterly different. 
 Starting from the facts of the world and of 
 human nature, the scientist will try so far as he 
 can to understand them, and where he fails will 
 be apt to lay the blame on his own faculties. At 
 all events, taking them as they stand, he will try 
 how human conduct may best be harmonized with 
 these fixed surroundings. It is only by accepting 
 the laws of nature that practical science pro- 
 gresses; and it is only by accepting the fixed 
 tendencies of man and society that we can hope 
 to improve mankind ethically and socially. 
 
RATIONALISM AND SCIENCE 71 
 
 II. 
 
 The moral is sufficiently obvious. It is of the ) ' 
 utmost necessity for the well-being and progress 
 of society that the sciences which have man for 
 their subject-matter should be earnestly pursued; 
 that they should be organized at our Universities, 
 that research in them should be made one of the 
 great ends of all higher education, that we should 
 set aside every weight and hindrance which may 
 prevent us from running this course with all the 
 energy which we possess. 
 
 Theoretically, perhaps, almost any thoughtful 
 person would concede this principle. Yet when 
 we come to look at education as it is, we see that 
 the practical means to this end are by no means 
 so generally conceded. We in England are in 
 this matter behind the nations of the Continent, 
 especially France and Germany. With us educa- 
 tion is still regarded as necessarily either literary 
 or scientific. By a literary education we mean an 
 acquaintance with certain languages an3 tHe 
 books written in them, a training whereby a man 
 acquires a good and correct stylejnjwriting. and 
 a knowledge of the way in which nature and the 
 great problems of life have been regarded, more 
 especially by the Greeks and Romans. In its 
 own way this training is admirable; I should be 
 one of the last to speak slightingly of it. For 
 four hundred years it has served to maintain a 
 high standard of literature and culture. It takes 
 
72 HUXLEY MEMORIAL LECTURES 
 
 the minds of the educated out of their narrow sur- 
 roundings into the broad spaces of Greek 
 thought. It keeps before us the imperishable 
 models of ancient beauty, the poems of Homer 
 and Virgil, the dramas of Euripides, the dialogues 
 of Plato, the lives of Plutarch, the statues of 
 Phidias and Praxiteles. If we were to forget or 
 to neglect these precious legacies of the past, we 
 should fall many degrees in civilization. Nor 
 less is the claim upon us of modern literature and 
 art in all their phases. But yet this culture leaves 
 lacunae. 
 
 By a scientific education men usually mean a 
 training in what is in this country regarded as in 
 
 _. nT -^ - rr^ in i -^^ 
 
 a special degree science, the natural knowledge 
 which begins with mathematics and ends with 
 biology, the study of the visible world, of nature 
 animate and inanimate. This training also is in 
 its way admirable ; it would be in me an imperti- 
 nence to attempt to write its panegyric. But has 
 it no tendency to drift into specialism, a narrow- 
 ing of the mind to a single small field of study 
 and observation? and is it free from the danger 
 of disposing those who too exclusively pursue it 
 towards materialism, and blindness to the higher 
 and more human side of life? The space left 
 between literary education on one side and scien- 
 tific education on the other, is in England very 
 imperfectly occupied. Human science is among 
 us the Cinderella, whose sisters are made much 
 of, while she has to take what they do not care for. 
 
RATIONALISM AND SCIENCE 73 
 
 And the fairy godmother does not arrive, but in 
 her place there come many spirits of delusion ; so 
 that the ground which should be occupied by 
 ordered knowledge is seized upon by all sorts of 
 charlatans, and becomes a hunting place for all 
 kinds of untrained intelligences. 
 
 I would earnestly plead for a better recogni- 
 tion, a more complete organization, a better 
 endowment for the studies of which man is the 
 subject matter. 
 
 They fall naturally into three groups. Firstly 
 we have the historic group, a series of sciences 
 philological, archaeological, and the like, the 
 purpose of which is to make the life of men in 
 the past live again in the present in all detail and 
 vividness. Nothing in that life is irrelevant, no 
 detail which can possibly be reached by research 
 is unimportant. Every touch of the brush helps 
 a great picture, and in the same way the discovery 
 of a few small documents illuminating some phase 
 of past history may be in its working quite revo- 
 lutionary. A ray of light falling on a spot hitherr 
 to obscure may shew a diamond. 
 
 The study of history has no doubt in most 
 places changed its character and methods, and 
 become more fully alive. But generally speak- 
 ing there is still too much in it of a merely literary 
 character; the enjoyment of the writings of his- 
 torians, however good in itself, cannot take the 
 place of an intense realization of the meaning of 
 
74 HUXLEY MEMORIAL LECTURES 
 
 the past to all of us, and an insatiable desire to 
 learn to the utmost what really took place. 
 
 Very often we hear a shameless avowal of con- 
 tempt for ' mere history/ f Let bygones be by- 
 gones/ men say ; ' we have to do with the present. 1 
 But the very problems which these men have to 
 solve in the present, have been attempted a thou- 
 sand times before in the course of history. Are 
 we to throw away all the results of human effort 
 and learn only by the education of failure what is 
 good for us? Would a biologist confine his 
 attention to the study of existing species of plants 
 and animals ? or would a chemist set aside as un- 
 worthy of study the results of the experiments of 
 his predecessors? So short is human life, and 
 so feeble the intelligence of man, that unless he 
 profits by the experience of past generations, he 
 will be falling back, not advancing in knowledge. 
 The truth is that the historian who discovers the 
 real line of human progress in the past, even in 
 some quite subordinate part of the field, does at 
 least as much for the well-being of mankind as 
 the man who discovers a new gas, or invents a 
 new mode of more rapid intercourse between 
 peoples. 
 
 Speaking in the light of my own studies I may 
 say that there are two periods of ancient history 
 which are of extreme interest to us moderns, not 
 only as picturesque in themselves, but as shewing 
 us the true working and results of many of the 
 social tendencies now prevailing. These periods 
 
RATIONALISM AND SCIENCE 75 
 
 are the age of the spread of Greek culture after 
 Alexander, and the early age of Christianity in 
 the Graeco-Roman world. These times are full 
 of modernity. The problems with which they 
 teem are our problems, and nothing is more cer- 
 tain than that factors which then worked will work 
 in the same direction now. Great shifts of popu- 
 lation to new regions, the drift of the dwellers in 
 the country districts towards the towns, the decay 
 of religious belief, vast wealth of a few and gall- 
 ing poverty of many, distaste for military service, 
 increase of divorce, a falling birth-rate, these and 
 many other modern tendencies were familiar two 
 thousand years ago. And men of those times, 
 men quite as wise as any of us, tried to devise 
 cures for these things, introduced some remedies 
 which were palliations for the diseases of society, 
 and some remedies which only increased the evils 
 they were intended to prevent. All these things 
 stand written in the history of the past. Are we 
 so wise or so self-confident as to disdain to learn 
 the lessons which history teaches ? Must we learn 
 only as do plants and animals, from the hard 
 lessons of suffering? 
 
 In this matter Germany has something to 
 teach. A French writer, M. P. Huvelin, writes 
 as follows : 
 
 * It is an enviable privilege of the Germans that 
 they realize without effort and by nature the rela- 
 tions between practical aims and disinterested 
 study. With them, new social and academic 
 
76 HUXLEY MEMORIAL LECTURES 
 
 needs give life not only to practical work, but to 
 scientific research. Examples abound. Does 
 Germany desire to acquire possessions beyond 
 the sea? At once there arises a literature on 
 colonial geography, methods of colonization, 
 colonial legislation. Does she wish to augment 
 her fleet? Her writers investigate history to see 
 if there exists a necessary connexion between a 
 powerful fleet and a prosperous commerce/ And 
 so forth. The picture may be, as regards Ger- 
 many, rather highly coloured; but it represents 
 what would happen in an ideal Germany, or in 
 any country which realizes the relations between 
 knowledge and action. 
 
 But it may be said that all the facts of ancient 
 history have been known by our ancestors for 
 generations, and have been taken into account by 
 our statesmen and publicists. Nothing could be 
 less true than such an assertion. We are only 
 beginning, by the help of exploration, excavation, 
 renewed study of historians, to understand what 
 really took place in the ancient world. The con- 
 ventional notions on the subject which we in- 
 herit from our fathers are as unlike the reality as 
 the engravings of the Tower of Babel which we 
 find in old illustrated Bibles are unlike the 
 palaces which actually existed at Babylon.* For 
 example we have begun in recent years to realize 
 how great a part in ancient history was played by 
 
 * No recently published work shews this more clearly 
 than Professor E. Meyer's Kleine Schriften. 
 
RATIONALISM AND SCIENCE 77 
 
 supply and demand of commodities, by desire of 
 fresh markets, by poverty and unemployment. 
 It is the course of events in our own days which 
 has thrown an entirely fresh light on ancient his- 
 tory. And if we only take the trouble to pay 
 attention, ancient history can in return throw a 
 flood of light on our own present and on the future 
 which awaits us. And what is true of ancient 
 history is quite as true of more recent history. 
 
 Secondly, we have the psychological group of 
 studies, which investigate the active and the 
 thinking powers of man, the conscious powers, 
 and that great realm of the unconscious which now 
 takes so great a place in our horizon. It is 
 astounding what great revolutions are wrought 
 alike in our conceptions of history and our practi- 
 cal activities in the world by the introduction of 
 truer views of the nature of human feelings, 
 habits and thoughts. Every practical man has to 
 deal with the minds of his fellows, and the 
 analogy of all other studies proves that he will 
 work far more effectually when he has an accurate 
 and methodical notion of what those minds are, 
 than he can when he merely knows them by rule 
 of thumb. Practical statesmen are often dis- 
 posed to think lightly of the methodical study of 
 man, yet could not any psychologist point to Acts 
 of Parliament and decrees of Emperors the 
 failure of which, from their want of conformity 
 to human nature, could quite well have been fore- 
 seen? 
 
78 HUXLEY MEMORIAL LECTURES 
 
 I must not venture to speak of a special side of 
 psychology which has been lately brought into 
 prominence, and in regard to which words from 
 Birmingham are greatly valued, the study of the 
 sub-conscious side of man. Hence has come in- 
 deed a great revelation. And I venture to say 
 that as regards human progress and human happi- 
 ness this great accession to our knowledge is 
 far heavier in the balances than such discoveries 
 as those of radium or of wireless telegraphy 
 which only touch human life on the outside. 
 
 Perhaps it is the new psychology of religion 
 which has, or is destined to have, the greatest 
 effect on our practical and ethical life. In recent 
 years there has been an immense deal of research 
 and of writing in regard to such matters as the 
 relations between reason and faith, or the con- 
 nexion between fact and doctrine, or the 
 phenomena of religious experience, which must 
 needs have a profound influence on the faith of 
 the Christian Church. It is now realized that 
 religion does not lie in the reception of certain 
 facts as historic, but in an attitude of the spirit; 
 and that attitude is the result of an immense his- 
 torical process. Like all great discoveries this 
 change sometimes dazzles the explorer. We 
 have perversions, as when some of the reactionary 
 parties, more especially the Jesuits, think they 
 can justify on psychologic grounds all the super- 
 stitions of the Middle Ages. But without going 
 this length we may see that too great reliance on 
 
RATIONALISM AND SCIENCE 79 
 
 reason greatly misled the Reformers of the six- 
 teenth century, making them develop rigid 
 schemes of theology almost regardless of the fact 
 that religious truth is relative, and belongs not 
 like mathematics to an abstract scheme of 
 thought, but to the ethical and practical side of 
 man. In a sense even the basest superstition has 
 some justification, for it could not have arisen but 
 for its satisfaction of some human need. But a 
 society is debased if it retains too long beliefs 
 suited to a barbarous age, but later tending to 
 dwarf the intelligence and fetter the freedom of 
 mankind. 
 
 Nowhere better than in Huxley's essay upon 
 Descartes is expressed the growing conviction of 
 investigators that all knowledge has a base in 
 psychology, that every fact has a subjective 
 element, that nothing can be seen but in a human 
 mirror. The relativity of knowledge to the know- 
 ing mind is the truth which has altered the basis 
 of all such branches of study as have to do with 
 man's thought and feeling, aesthetics, religion, 
 even economics ; has destroyed their abstract and 
 rationalist character, and drawn them into the 
 ways of scientific method. 
 
 Thirdly, there is the group of studies included 
 in sociology. In England in past days we made 
 the mistake of setting apart one class of social 
 phenomena, the facts of the production and dis- 
 tribution of wealth, and supposing that the Politi- 
 cal Economy which is concerned with these can 
 
8o HUXLEY MEMORIAL LECTURES 
 
 be dealt with apart from all other phenomena of 
 society. This is in the long run impossible. We 
 may of course have Political Economists as 
 specialists, just as we have Physicians who make 
 a speciality of the lungs or the throat or the eye. 
 But after all the health of a body depends upon 
 all the parts working together, and the well-being 
 of a nation depends not only upon its wealth but 
 upon its efficiency in all fields of human activity. 
 When one considers what must finally be included 
 in sociology, all the studies which have to do with 
 man in society, from eugenics and political 
 economy on one wing to ethics and religion on 
 the other, one feels that our society has reached a 
 point like the summit of Pisgah, whence the 
 promised land may be seen in all its beauty and 
 fertility, a land, however, which has to be reached 
 through much toil and many wars. The land is 
 not yet even thoroughly surveyed; we have no 
 good map of it, and we are dependent on the 
 reports of solitary workers who have made their 
 way into one or another of its many regions, and 
 brought back weighty loads of fruit. 
 
 Let me take a concrete example. Lately I 
 had the pleasure to take a modest part in an im- 
 portant conference held in London on the subject 
 of town-planning. In the last ten years it has 
 dawned upon the people of Europe and America 
 that the planning of towns has hitherto been quite 
 at the mercy of accident, that private owners, 
 looking only to their own interests, have sue- 
 
RATIONALISM AND SCIENCE 81 
 
 ceeded in making our cities very far from what 
 they should be, without unity of plan, without 
 consideration for the general convenience, quite 
 unfit to serve many of the purposes of civilization. 
 And there have sprung up in England, France, 
 Germany and America, not merely a few, but 
 hundreds of societies pledged as far as may be 
 to remedy these evils, to make our cities more 
 orderly in arrangement, more healthy, more 
 cleanly, free from the thousand nuisances which 
 make our lives dull and ugly, free from palls of 
 smoke and the blatant vulgarity of pushing 
 advertisements. Here indeed is a movement 
 which stirs the pulses of men ! Here are ideals 
 which can only be attained by method and 
 thought, that is to say by science. But the 
 science by which they are to be reached is not 
 mere constructive skill, nor the art of gardening, 
 of paving or of building. It is essentially human 
 science, and has a place in all three of the sections 
 which I have mentioned. We want to know with 
 accuracy what purposes men work with, what are 
 the laws of health, what contributes to beauty and 
 what overwhelms us with ugliness. We want 
 also to study social conditions, the tenure of land, 
 the divisions of employment in a locality, the 
 needs of future generations, in order that we may 
 learn to subordinate the interests of individuals 
 to the general good, and to make our societies 
 really healthy and progressive. Unless the laws 
 of man and of society are first considered, our 
 
82 HUXLEY MEMORIAL LECTURES 
 
 plans will be struggles towards an unknown end. 
 They will be like planning a shell for a marine 
 creature of unknown size and habits, like build- 
 ing a house without knowing what sort of a family 
 is to live in it. 
 
 The organizers of that Conference arranged 
 that their proceedings should begin with papers 
 on town-planning in the past, by the Greeks, the 
 Romans and the Europeans of the Renaissance. 
 These predecessors of ours had to face, not pre- 
 cisely our problems, but problems similar to ours. 
 Cities like Rhodes and Antioch, Alexandria and 
 Pergamon were laid out by architects whose 
 technical skill was almost equal to that of their 
 modern successors, and to whom the utmost free- 
 dom was given to make a city, with its walls and 
 market place, its temples, gymnasia and streets, 
 on the most scientific principles. It would be 
 absurd that when a federal capital has to be built 
 for Australia or India, or a great city like Chicago 
 to be spread out on a plain, the lessons of the 
 past should not be used to the utmost, and hints 
 taken from all available records. Surely here is 
 an example which justifies my contention that for 
 wise action in the present, and for far-seeing 
 plans for the future it is above all things neces- 
 sary that our knowledge of man and of his history 
 should be as exact, as detailed and as vivid as 
 possible. 
 
RATIONALISM AND SCIENCE 83 
 
 III. 
 
 When we consider how rapid has been the pro- 
 gress in recent times of physical and biological 
 sciences, and realize how slow in comparison has 
 been the progress in the knowledge of man, we 
 may almost despair. We can scarcely say that, 
 in many important respects, we know more of the 
 nature of human well-being than was known by 
 Aristotle. Yet in some countries, more especi- 
 ally in Germany and America, at least the magni- 
 tude of the task and the infinite importance of 
 reaching sound and trustworthy results are 
 beginning to be recognised. 
 
 As the nineteenth century was the great age of 
 discovery in the sciences of nature, so, I venture 
 to prophesy, the twentieth century will be the 
 great age of discovery in human science. Com- 
 pared with our mastery of the forces of nature, 
 our mastery of ourselves and our destiny is in an 
 infantile stage. We see how utterly defective 
 are the arrangements of society around us. We 
 see how our medicine is capable of grappling with 
 definite diseases, but has no ideal of human 
 health, how our skill produces an infinite mass of 
 wealth, and then distributes it in a way that is 
 simply appalling. We see how marriage remains 
 at the mercy of the worst regulated impulses of 
 our nature, without any thought of the future of 
 the race. We see how charitable feelings to- 
 wards our fellow men, instead of being a raising 
 
84 HUXLEY MEMORIAL LECTURES 
 
 force in the world, tend constantly, through sheer 
 want of method and wisdom, to degrade a great 
 part of the people, and to promote the shiftless- 
 ness of the idle, and the multiplication of the 
 unfit. These things brood in the hearts of all 
 who try to look with unblinded eyes on modern 
 society. And there comes among us a constant 
 stream of would-be reformers, who see the evil 
 and have a nostrum of their own to cure the ills 
 of the world. As in the Middle Ages men sought 
 a philosopher's stone, the touch of which would 
 turn all substances to gold, so these social 
 alchemists recommend some hastily adopted salve 
 as sovereign for all the ills of society. When 
 their remedy takes the form of the foundation of 
 some socialist society, at all events it is an experi- 
 ment from the failure of which mankind may learn 
 much. But if such experiments are to be first 
 tried on whole nations, it is terrible to think what 
 misery and destruction will be caused. 
 
 The only true course is for practical experi- 
 ments to follow in the wake of systematic know- 
 ledge. Systematic knowledge cannot give us 
 ideals; they must arise within, and cannot be 
 gained by study of fact and condition. But un- 
 less the ideals are pursued with a knowledge of 
 history and of human nature the result can only 
 be disappointment and disaster. 
 
 It seems to me that in our days everyone who 
 desires extensive changes in the frame of society 
 calls himself a socialist. As a result the most 
 
RATIONALISM AND SCIENCE 85 
 
 discordant views and purposes are covered by 
 that convenient term. The Marxian school of 
 socialists on the Continent have as their avowed 
 object the improvement of the economic condition 
 of the manual workers, the securing for them of a 
 greater share in the world's produce by means of 
 a kind of social war. In England this is regarded 
 as the main function of the trades unions; and 
 with us the term socialism covers a much wider 
 variety of views, from the desire of simpler and 
 less ostentatious living to dislike of all existing 
 institutions. And everyone who chooses to call 
 himself a socialist thinks that he may dogmatize 
 as to what socialism really is. One theorist will 
 tell us that it implies the expropriation of all the 
 owners of material resources. Another will say 
 that it is not compatible with the present organiza- 
 tion of the family. A third will regard it as 
 bound up with secularity, and incompatible with 
 the Christian religion. And so forth. But I 
 would venture to submit, that socialistic theories 
 and experiments have been going on in the 
 civilized world from the very beginning of his- 
 tory. Plato opened an aera of speculation on 
 the subject in his immortal Republic; and in the 
 days of Plato there existed a community, that of 
 the Spartans, in which socialist ideas had more 
 full course in practical life than they have had 
 in any commonwealth since. So the study of 
 history must claim its right before we can venture 
 to say that we know much about socialism. And 
 
86 HUXLEY MEMORIAL LECTURES 
 
 the study of man as an individual and of man in 
 society claims its rights; for if we assume human 
 nature to be other than it is, our whole construc- 
 tion is built of unsound materials, and will topple 
 into ruins as fast as we build. Men are the bricks 
 of which any community must be built, and we 
 must know what strain those bricks will stand, 
 and whether they can resist wind and rain. I 
 take it that the only true basis of socialism lies in 
 the idea that the good of individuals must be sub- 
 ordinated to the good of the community. Here 
 we are all agreed. But we come at once to 
 the question what is the good of the community, 
 and how is it to be promoted? 
 
 If socialism implies a belief in the perfect 
 equality of the sexes, then the Maker of the 
 world certainly is not a socialist, for He has given 
 the two sexes different faculties, and imposed on 
 them different tasks. If socialism wishes to 
 abolish the family, it must discover motives suffi- 
 cient to induce men and women, apart from the 
 old family motives, to observe the rules of 
 morality and to greatly desire to have descend- 
 ants. If socialism wishes to make the state the 
 universal employer it must find out how to secure 
 energy and honesty in those who direct, and 
 docility and industry among those who labour, 
 apart from the hard discipline of the struggle for 
 existence which at present keeps society going, 
 whether better or worse. It is possible that as 
 we have superseded sailing vessels by steamships, 
 
RATIONALISM AND SCIENCE 87 
 
 and horse traction by motor traction, so we may 
 be able some day to discover an organization of 
 society which will be more economic of force and 
 productive of better results than the organizations 
 of the past. But the only safe road to the goal 
 is the same road which has been followed in our 
 improvements in communication. First we had 
 the man of science in his laboratory making ex- 
 periments, weighing results, eliminating friction, 
 examining materials. Then we had modest ex- 
 periments on a small scale, at first experiments 
 with mere playthings; and these experiments 
 gradually grew in scale because they succeeded, 
 until, in branch after branch of transport, the new 
 methods competed with the old, and fairly beat 
 them out of the field. When motors were first 
 heard of we did not proceed to slaughter all our 
 horses, and when aviation is beginning to succeed 
 we do not break up our railways. Yet that is the 
 way in which some of the speculative schools of 
 socialism would go to work on the organization 
 of society. Newton, the greatest of our men of 
 science, claimed to excel his contemporaries only 
 in patience or persistency. And it is this active 
 patience, patience in research, patience in con- 
 forming to the conditions of the world, patience 
 in enduring what cannot be altered, and in 
 gradually changing what can be altered, which 
 must be the essential feature of all reform, unless 
 we would fling away all the rich results of the 
 
88 HUXLEY MEMORIAL LECTURES 
 
 striving and sufferings of our ancestors, and run 
 the risk of relapse into a state of barbarism. 
 
 I think we may in this matter see clearly the 
 contrast between the rationalist and the scientific 
 tendencies in the remoulding of society. In the 
 French Revolution, for example, the guiding 
 principle was a regard for certain assumed human 
 rights. In order to secure those rights every- 
 thing was thrown into the melting pot. No doubt 
 the world learned a great deal of wisdom from 
 the reckless experiments of those stormy days. 
 But to what did they lead ? To Napoleon, and a 
 militarism which deluged Europe with blood, and 
 brought upon France a depression from which 
 she has not yet recovered. The custom of 
 science when it sees things going amiss, is not to 
 leap like Curtius into the opening gulf, but to 
 interrogate history and experience, to see when 
 such evils before existed, and how they were met, 
 where such evils are in our day not to be found, 
 and the reason why. This method requires 
 patience both passive and active, passive patience 
 to bear the evils until we have fair prospect of a 
 remedy, and active patience or persistence to 
 bring together all the facts, to examine theory 
 after theory and make experiment after experi- 
 ment on a small scale, until we find a way which 
 is certainly a thoroughfare. A science which is 
 at home amid the facts of geology and of past 
 history will strongly believe in the possibilities 
 of progress; but it will also be very anxious not 
 
RATIONALISM AND SCIENCE 89 
 
 hastily to throw away anything which has in it the 
 germs of future amelioration. 
 
 Here, it seems to me, lies the greatest task of 
 our Universities in the immediate future. Be- 
 sides keeping up the standard of literary culture 
 on the one hand, and studying physical science 
 largely with a view to practical results on the 
 other, we want to found great schools of human 
 science, schools not starting with any settled 
 theories, but working hard to map out the field, 
 to find the true line of progress in past history, to 
 discern of what human nature is capable, and of 
 what it is incapable. We need both research, and 
 as a corrective to research the foundation of 
 classes of workers who may test the practical 
 validity of the theories formulated by researchers. 
 And we need these schools especially in Eng- 
 land. For we are told by all our best advisers 
 that England is falling behind other countries in 
 method and in practical efficiency. In past days, 
 from the time of Locke to that of Darwin, great 
 scientific movements have commonly started in 
 England. There is no reason why we should not 
 at least equal other nations in exploring the vast 
 field of the orderly knowledge of mankind. 
 
 It may be said that this task will naturally fall 
 rather to the older Universities, where Humani- 
 ties flourish, while the newer foundations neces- 
 sarily devote themselves to studies of more imme- 
 diate practical application. There is no doubt 
 force in this suggestion. But the older Universi- 
 
90 HUXLEY MEMORIAL LECTURES 
 
 ties are dominated, in a degree which is hardly 
 realized by those who have not taught there, by 
 traditional ways of thought. They do not greatly 
 encourage research; and the energies of their 
 ablest men are mostly absorbed in teaching on 
 well-established lines. The newer Universities 
 have at least greater freedom, and greater power 
 of self-adaptation to new needs. I remember 
 reading the first address of your Chancellor to 
 this University ; and it seemed to me that although 
 he was no professed savant, yet he had a broader 
 and a saner notion of the functions of a University 
 than was usually current in the older academic 
 bodies. You are the brain of a great working 
 community ; and such a community needs to think 
 not only of business success, but of all sides of 
 human life and action. 
 
 I know that you have in Birmingham had your 
 attention called before to the overwhelming im- 
 portance of human science. Some of my dis- 
 tinguished predecessors, Sir Francis Galton and 
 Mr. Karl Pearson have spoken here with the 
 greatest ability and the highest authority on the 
 question of heredity, and other subjects which are 
 on the border-line between biology and the 
 humanities. Doubtless these and similar studies 
 are pursued here in some degree by teachers. It 
 is difficult to over-express our obligations to those 
 who carry on researches which have such direct 
 bearing on the future of mankind. In such 
 matters as these I am only a learner. But I have 
 
RATIONALISM AND SCIENCE 91 
 
 given serious attention to two branches of the 
 group of historic studies, those concerned with 
 Ancient Greece and the Origins of Christianity. 
 Even in purely historic studies such as these we 
 greatly need a new spirit and better methods. 
 Above all we need to feel that the whole history 
 of the human race is one ; and that everything that 
 has ever happened in the human field may be a 
 light to the present. While investigators, 
 hemmed in by the narrow space of human life, 
 can but master the phenomena of some few 
 phases of history or some aspects of society, all 
 are really working together for a common end. 
 
 I have tried to shew that whereas great im- 
 pulses and ideas come from the unseen, the 
 manner of their working in the world falls within 
 the field of conscious thought and endeavour. 
 And intellect is turning more and more from the 
 attempt to reconcile them with accepted prin- 
 ciples, after the manner of the leaders of the 
 French Revolution and the framers of the 
 American constitution, towards the consideration 
 of their results in experience. In our days 
 democracy has arrived, and has come to stay. 
 We have to educate our masters, and in the first 
 place to instruct them as to what really has hap- 
 pened, and does happen in the world. And it 
 seems to me that the average citizen, the man 
 who now governs the world, will soon be more 
 ready to listen to the proved results of experience 
 than to any sort of a priori appeal. To go no 
 
92 HUXLEY MEMORIAL LECTURES 
 
 further than to the last general election, it was 
 very notable how on most platforms the appeal 
 was to results and consequences. The average 
 man is being more and more completely trained 
 to the notion that there is a fixed order in the 
 world, and that events do not happen at random. 
 He is now ready in matters of physical science to 
 take the word of those who have been trained, 
 those who really know. He does not perhaps yet 
 recognize so completely that the events of history 
 and of human society may also be matters of 
 definite knowledge, and considering how unripe 
 is most of the fruit of the knowledge of mankind 
 which is offered him, we can scarcely wonder that 
 he does not altogether relish it. That only shews 
 how much remains to be done in this field. We 
 are used to hearing men set forth the patent evils 
 of society, and then at once leap to the propound- 
 ing of some remedy warranted to set everything 
 right. It is the same procedure with which we are 
 familiar in the advertisements of quack medi- 
 cines. ' Do you feel languid, out of spirits ; have 
 you internal pains? Then try our pill or our 
 ointment.' In the same way those who see the 
 evils of modern society jump at some remedy, 
 some form of socialism it may be, or eugenics, or 
 female suffrage; and set it up as a general 
 remedy. The intermediate stage of studying in 
 what particular way each evil may be met they 
 overlook. What has to be insisted upon is that 
 between the perception of an evil and the pro- 
 
RATIONALISM AND SCIENCE 93 
 
 pounding of a remedy there is need for infinite 
 care and investigation, a process which must not 
 be slurred over or abridged, and which involves 
 the keenest exercise of the wisest among us for 
 generations. Here is the opportunity of our 
 Universities. 
 
 In human science it is far more important than 
 even in the science of the material world to avoid 
 superficiality and extreme specialism. As man 
 is an unit, all the studies which bear upon him 
 and explain him must be kept together and their 
 results harmonized. Not good but evil would 
 result, if the recognition of human science were 
 to take the form either of teaching superficial 
 rules from books about psychology or pedagogy, 
 or of encouraging a minute subdivision of the 
 field into small plots in which jealous specialists 
 should sit keeping watch against any infringe- 
 ment of their domain, and fully convinced, each 
 of them, that he alone possesses the key of know- 
 ledge which should guide conduct. As I have 
 observed, man is an unit, and whether as an indi- 
 vidual or in an assembly he must pursue one 
 course and repudiate other courses. The 
 grounds of action have to be taken from a number 
 of different studies; the line of action is neces- 
 sarily a compromise, and influenced by a great 
 variety of motives. Hence the narrow specialist 
 who thinks the particular results at which he has 
 arrived ought at once to dictate conduct, is as 
 fatal a leader as are the rationalist charlatans of 
 
94 HUXLEY MEMORIAL LECTURES 
 
 whom I have spoken. Great collators of results 
 and systematizers of knowledge are a prime 
 necessity of the situation. And they will need 
 the highest faculties which human nature can 
 grow. 
 
 I should not of course commit the absurdity of 
 suggesting that all attempts at improving social 
 conditions should be suspended until we have a 
 more precise knowledge of what their results are 
 likely to be. Practical experiments must go on, 
 and they must needs do something to increase 
 the bounds of our knowledge, whether they are 
 successful or not. But I would venture to urge 
 the great need of more complete organization and 
 better endowment for human studies. 
 
 If the question be asked how these studies may 
 be organized, the answer seems to be that as they 
 develop they will organize themselves, and each 
 branch of the tree will find its due place. In 
 human science as in natural science one cannot 
 cultivate any part of the field without increasing 
 the productiveness of the whole. A man who 
 gives most of his life to the discovery of a new 
 chemical element, and a man who gives most of 
 his life to the examination of the marks on the 
 backs of crabs or to the respiratory organs of frogs 
 are equally the children of science, and workers 
 in the cause of light. In the same way men will 
 equally be of service to historic science whether 
 they study the antiquities of Greece, or the insti- 
 
RATIONALISM AND SCIENCE 95 
 
 tutions of the Middle Ages, the faculties of man 
 or the working of economic laws. All knowledge 
 is really one; and all men of science are what 
 Comte called them, in a sense the priests of 
 humanity. 
 
 But to come for a moment to a more practical 
 point of view, I may venture to affirm, from the 
 experience of half a life time in University teach- 
 ing, that for the due cultivation of any branch of 
 science in a University two things are necessary. 
 First institutes, workships with a settled place for 
 working, with apparatus of all sorts and specialist 
 libraries. For such purposes an ordinary library 
 is insufficient; the books must be within reach, 
 and one must be able to turn them over and criti- 
 cize them in the presence of fellow-workers. 
 The second thing that is necessary is research 
 studentships, that the workers may at least be 
 able to live while they devote themselves for the 
 good of the community. Whether any such insti- 
 tutes exist at Birmingham I know not; but I am 
 sure that sufficient provision of this kind is not 
 made in any of our English Universities. For 
 work in anthropology, archaeology, statistics, 
 psychology, workshops are as necessary as they 
 are for chemistry or anatomy. 
 
 It may be regarded as a paradox if one affirms 
 that studies which deal with the remote past or 
 with obscure barbarous tribes in Africa or 
 Australia have much to do with practical ethics 
 
96 HUXLEY MEMORIAL LECTURES 
 
 and sociology. In the pursuit of physical science 
 men have passed this stage of objection. No one 
 would find it difficult to understand that technical 
 chemical researches may have a bearing on the 
 selection of the food we eat, or that biological 
 studies like those of Darwin may have great value 
 in the field of human action and morals. Why 
 then should we doubt that special and minute 
 studies in history and psychology may be a guide 
 to conduct in the present? In all branches of 
 science one pursues the truth for its own sake; 
 but one reaches a result of practical advantage, 
 a far richer result probably than one could ever 
 have attained by limiting one's investigation to 
 what appeared to be fruitful subjects. 
 
 The sum of the matter is this. Three appeals 
 are possible in justification of lines of action. 
 The first, that to authority, is passing out of 
 favour. The second, that to fixed principles, 
 must always be of value to all who try to think 
 consistently : but in the haste and confusion of 
 modern life it does not convince people as it used. 
 The third, that to fact and experience, falls in 
 very much with the tendencies of the times; and 
 therefore it is the bounden duty of those who 
 have leisure and intelligence to organize it, to 
 endow it, to give it a great place in our Universi- 
 ties. If it be taken up in a rash and hasty mood, 
 it may lead the human race into infinite trouble. 
 But if taken up in the true spirit of science, 
 modest, slow to affirmation, given to testing again 
 
RATIONALISM AND SCIENCE 97 
 
 and again every result, it may furnish the spirit of 
 progress with data of inestimable value, and give 
 us in time a complete chart of the ocean of human 
 life over which we all have to guide our course. 
 
99 
 
 LIFE AND CONSCIOUSNESS.* 
 By Prof. Henri Bergs on. 
 
 Generally speaking, when a lecture is dedi- 
 cated, as this is, to a thinker or scientist whose 
 name it bears, the lecturer has to make an effort, 
 at times an effort of some difficulty, to maintain 
 himself, by the choice of his subject, in the sphere 
 of interests of this thinker or scientist. But, for 
 a lecture associated with the great name of 
 Huxley, no such effort is necessary. Rather, in- 
 deed, we may ask what scientific question, what 
 philosophic problem, is there which did not 
 interest that luminous intellect one of the 
 broadest and most comprehensive that nine- 
 teenth-century England produced, fertile in great 
 intellects as it was? 
 
 It has seemed to me, however, that the ques- 
 tion of consciousness in general of its relations 
 with nature and life corresponds fairly well with 
 one of the main lines of Huxley's thought, with 
 one of his chief pre-occupations. And as I per- 
 sonally know none more important nor more 
 crucial in the whole range of philosophy, that is 
 the subject I have chosen. 
 
 * The " Huxley Lecture," delivered at the University of 
 Birmingham, May 29, 1911, with some additions. 
 
ioo HUXLEY MEMORIAL LECTURES 
 
 But, before attacking the problem itself, there 
 is one point to which I wish to call your attention 
 namely, the meagre light thrown on this prob- 
 lem by the " systems " of philosophy properly 
 so-called. What are we? What are we doing 
 here? Whence do we come and whither do we 
 go? These, it seems, are the essential and vital 
 questions, the questions of supreme interest, 
 which first present themselves to the philosopher 
 and which are, or should be, the very cause of 
 philosophy's existence. But not at all. If we 
 consider the enormous work done in philosophy 
 from antiquity down to the present time, we find 
 that attention has been engrossed with a host of 
 special problems in psychology, in morals, in 
 logic, as well as a crowd of very general meta- 
 physical speculations on the more or less hypo- 
 thetic principles of things; and then again we 
 find a welter of critical reflections on the manner 
 and method of knowledge, and finally a multi- 
 tude of works of history and discussion which 
 give us the opinions of thinkers on the opinions 
 of others; but we perceive that those problems 
 which interest us as human beings above all else, 
 and which are for us the vital problems, have 
 very seldom been squarely faced. I mean that 
 the solution given has been thrown out in pass- 
 ing, as a consequence of certain very general and 
 highly abstract conceptions of Being, of Thought, 
 of Extensity, of Substance, etc. It seems as if 
 philosophy thought it would be slighting the 
 
LIFE AND CONSCIOUSNESS 101 
 
 claims of these problems, failing ih ; iespiect" -fa 
 them, to study them in the same way as an 
 ordinary question of biology or history, which 
 cannot be resolved save in an approximate, im- 
 perfect and provisional manner. No; it seems 
 that for the answer to these great problems some 
 great system is necessary in which solemnly and 
 immutably it may take its place, as a geometrical 
 theorem takes its final place in a book of Euclid. 
 The disadvantage of this way of proceeding is 
 that we thus put in the second place problems 
 which should be in the first; but, besides that, we 
 render the solution of these problems dependent 
 on general systems of philosophy, with which they 
 stand and fall. And then the solution shares in 
 the strictness and rigidity of the system to which 
 it is attached; it must be taken or left, just as it 
 is, and admits of no gradual development or 
 perfecting. 
 
 Either I am much deceived or the future 
 belongs to a philosophy which will give back to 
 these problems their rightful place the first! 
 which will face them in themselves /and for them- 
 selves, directly; which, no longer returning to 
 these questions an answer deduced from syste- 
 matic principles (a self-styled " final " solution, 
 to be replaced in its turn by other solutions which 
 will claim equal finality), will be gradually per- 
 fectible, open to corrections, to retouchings and 
 unlimited amplifications; a philosophy that will 
 no longer pretend to have reached a solution of 
 
102 'HUXLEY MEMORIAL LECTURES 
 
 mathematical certainty (which mathematical cer- 
 tainty, in such a case, must always be deceptive), 
 but will be content (like a good number of 
 sciences at the present time) with a sufficiently 
 high degree of probability, with a probability 
 capable of being pushed farther and farther till 
 it becomes so great that it may end by becoming 
 practically equivalent to certainty. In short, I 
 am of opinion that there is no absolutely certain 
 principle from which the answer to these ques- 
 tions can be deduced in a mathematical way. 
 Nor does there exist a privileged fact, or a col- 
 lection of privileged facts, from which the answer 
 can be inferred, as, for example, occurs in a 
 problem in physics or chemistry. But it seems 
 to me that in a great number of different fields 
 there is a great number of collections of facts, 
 each of which, considered apart, gives us a direc- 
 tion in which the answer to the problem may be 
 sought a direction only. But it is a great thing 
 to have even a direction, and still more to have 
 several directions, for at the precise point where 
 these directions converge might be found the 
 solution we are seeking. What we possess mean- 
 while are lines of facts, none of which goes far 
 enough, none of which goes right up to the point 
 which interests us and at which we want to place 
 ourselves ; but these lines may be more and more 
 prolonged, and they, moreover, already suffi- 
 ciently indicate to us, by the ideal prolongation 
 
LIFE AND CONSCIOUSNESS 103 
 
 that is open to us, the region in which the answer 
 to the problem will be found. 
 
 Now, it is some of these lines that I desire to 
 follow with you to-day. Each of them, taken 
 apart, will give, I repeat, nothing but a proba- 
 bility ; but all together, by converging on the same 
 point, may give us an accumulation of probabili- 
 ties which will gradually approximate scientific 
 certainty. 
 
 Here is the first line I wish to follow, the first 
 aspect of the question that I wish to point out to 
 you. What we call " the mind " is, before all, 
 something conscious it is consciousness. But 
 what do we mean by consciousness ? You rightly 
 guess that I am not going to define this simple 
 thing which eludes all definition, and which every- 
 one can experience. But, without exactly giving 
 a definition which would be much less clear than 
 the thing defined, we may at least indicate its 
 most obvious and most striking character. Con- 
 sciousness signifies, above all, memory. The 
 memory may not be very extensive; it may 
 embrace only a very small section of the past, 
 nothing indeed but the immediate past; but, in 
 order that there may be consciousness at all, 
 something of this past must be retained, be it 
 nothing but the moment just gone by. A con- 
 sciousness which retained nothing of the past 
 would be a consciousness that died and was re- 
 born every instant it would be no longer 
 consciousness. Such is just the condition of 
 
104 HUXLEY MEMORIAL LECTURES 
 
 matter ; or, at least, such is just the way we repre- 
 sent matter when we wish to oppose it to 
 consciousness. Leibnitz defined matter that is 
 to say, what is not consciousness by calling it a 
 momentary mind, an instantaneous consciousness. 
 And, in fact, an instantaneous consciousness is 
 just what we call unconsciousness. All conscious- 
 ness, then, is memory; all consciousness is a 
 preservation and accumulation of the past in the 
 present. 
 
 But, on the other hand, all consciousness is an 
 anticipation of the future. Analyse your mental 
 state when you hear someone speaking : you are 
 intent on what is being said, but also on what is 
 coming; and even the present only interests you 
 in so far as it will profit the immediate future. 
 We are essentially drawn and, as it were, inclined 
 towards the future, because we are creatures of 
 action, and every action is like a leap into the 
 future into the next moment. 
 
 So that to remember the immediate past and to 
 anticipate the immediate future is the most strik- 
 ing function of consciousness. Indeed, what we 
 call the present instant is something that hardly 
 exists except in theory, for it has already ceased 
 to exist when it attracts our attention. Try to 
 'catch the present instant, it has already gone, it 
 is already far away. Practically, what we call 
 our present is something that has a certain length 
 or breadth of duration, and is composed of two 
 halves, one being our immediate past, the other 
 
LIFE AND CONSCIOUSNESS 105 
 
 our immediate future. What we feel ourselves 
 to be at any given moment is what we were just 
 before and what we are just about to be : we re- 
 cline on our past and incline towards our future, 
 and that reclining and inclining seem to be the 
 very essence of our consciousness. So that con- 
 sciousness is, above all, a hyphen, a tie between 
 past and future. Now what is the use of such a 
 tie, and what is consciousness called upon to do? 
 To reply to this question, we must first ask what 
 are, in the whole of Nature, the creatures which, 
 to all appearances, are conscious beings. To 
 tell the truth, in order to be absolutely sure that a 
 being is conscious like ourselves, we ought to 
 penetrate it, to be it. Here, again, if we seek for 
 mathematical certainty, we shall obtain nothing, 
 for you cannot even be mathematically sure that 
 I, who am speaking to you at this moment, possess 
 a consciousness. I might be a well-constructed 
 automaton going, coming, speaking without 
 internal consciousness, and the very words by 
 which I declare at this moment that I am a con- 
 scious being might be words pronounced without 
 consciousness. However, though this is mathe- 
 matically possible, and consequently the existence 
 of my consciousness cannot be for you a matter 
 of mathematical certainty, I think that it is suffi- 
 ciently probable for you. The truth is, that 
 whenever you assume consciousness in a being 
 other than yourself, you infer this consciousness 
 from certain outward analogies that you find 
 
io6 HUXLEY MEMORIAL LECTURES 
 
 between this being and yourself. So let us follow 
 up this reasoning by analogy, and ask ourselves 
 up to what point it is probable that consciousness 
 may be imputed to nature, and at what point it 
 probably stops short. 
 
 One reply sometimes made to the question is 
 this : In ourselves, consciousness is bound up in 
 one way or another with a brain; we may there- 
 fore assume the presence of consciousness in all 
 those living beings in whom a brain is found, and 
 in those alone. But a moment's reflection will 
 show us the fallacy of this reasoning. For in 
 applying elsewhere this mode of argument, we 
 might as well say : digestion in us is bound up 
 with a stomach, therefore we ought to attribute 
 the faculty of digestion to the living beings who 
 possess stomachs, and to those alone. Now this 
 would be absolutely wrong, for living beings who 
 have no stomachs and even no organs, which con- 
 sist of a simple protoplasmic mass, are still able 
 to digest. Only, in proportion as the organism 
 becomes more perfect, a division of labour is 
 brought about : special organs are destined to 
 diverse functions instead of the whole mass doing 
 all, and the digestive faculty becomes localised in 
 a stomach and in other organs which accomplish 
 it better -, whilst the rest of the organism renounces 
 the faculty, having got rid of this care by putting 
 it on to a special organ. But the function was 
 previously performed in the undifferentiated 
 organism : it was performed all over it, though 
 
LIFE AND CONSCIOUSNESS 107 
 
 with less precision. Now, without doubt, in our- 
 selves consciousness is bound up with a brain in 
 some way, but as we descend in the animal scale 
 we see the brain become more and more simpli- 
 fied (as also does the whole nervous system), and 
 then the nervous centres separate from each other, 
 until finally the nervous elements are merged in 
 the mass of undifferentiated living tissue. Now, 
 is it not probable that if, at the top of the organic 
 scale, clear and distinct consciousness is bound 
 up with a brain and a highly differentiated 
 nervous system, consciousness accompanies this 
 system the whole length of the descent, and that 
 ultimately, when the nervous substance is merged 
 in the rest of living matter, consciousness itself is 
 diffused in the whole of this mass : diffused, con- 
 fused, weakened, but not reduced to nothing? 
 So that, in the end, consciousness might exist in 
 Nature wherever there is living matter. At least, 
 it is not impossible. But is it actually the case? 
 I believe it would be going too far, and here is a 
 fresh line of considerations which will, I think, 
 lead us to limit this conclusion to a certain degree. 
 We have just said that in the conscious being 
 that we know best namely, man consciousness 
 appears in some way to be bound up with a brain. 
 Since in this case it is through a brain that the 
 consciousness works, and since the work is thus 
 performed with the greatest precision, let us 
 glance at the brain, and ask ourselves what are its 
 most obvious functions. The brain, as you 
 
io8 HUXLEY MEMORIAL LECTURES 
 
 know, forms part of a whole called the cerebro- 
 spinal nervous system, which, in addition to the 
 brain itself, comprises the spinal cord, the nerves, 
 etc. In the spinal cord are set up mechanisms 
 which permit the various parts of our body to 
 perform complicated and well co-ordinated move- 
 ments. These mechanisms may be set in action 
 without the intervention of the brain, under the 
 direct influence of an external stimulus; in such 
 a case, the bodily reaction follows immediately 
 on the stimulation. But there are cases in which 
 the external stimulus, instead of obtaining at 
 once, through the spinal cord, an appropriate 
 bodily reaction, goes up to the brain, in order to 
 come down again thence to the spinal cord, and 
 only then obtains from the cord the complex 
 physical movement. Why did it go to the brain ? 
 And what has it gained by this roundabout pro- 
 ceeding? A glance thrown on the general struc- 
 ture of the brain will answer these questions. 
 The brain is in communication with those 
 mechanisms of the spinal cord that we have just 
 referred to, and can send to any one of them the 
 order to work. Imagine a stimulation coming to 
 the brain from without, by the eye, ear or touch. 
 The brain is like a switch having the faculty of 
 putting the current thus received in communica- 
 tion with one or other of the motor mechanisms of 
 the spine, chosen at will. So that in sum, and 
 broadly speaking, the spinal cord is a storehouse 
 of ready-made complex actions, and the brain is 
 
LIFE AND CONSCIOUSNESS 109 
 
 the organ permitting choice, in any circumstances, 
 of that particular complex action which is appro- 
 priate. The brain is the organ of choice. 
 
 Now, according as we descend in the animal 
 scale, we see that the functions of the brain and 
 those of the spinal cord become less differ- 
 entiated, as if a part at least of the faculty of 
 choosing, which in us is attached to the brain, had 
 descended to the spinal cord. In this latter, 
 then, we see that the mechanical attachments are 
 fewer, and probably also constructed with less 
 precision. Finally, it seems indeed as if the two 
 functions, the one an absolutely precise auto- 
 matism, the other an absolute faculty of choice, 
 become mingled, and blend with each other so 
 thoroughly that when we arrive at organisms in 
 which there are only a few heaps of nerve-cells 
 scattered here and there, and even more so when 
 we come to organisms where there are no longer 
 differentiated nerve-cells, we are faced by a 
 living substance such that external stimulus pro- 
 vokes from it a reaction both undecided, though 
 not altogether chosen (there comes in the element 
 of choice), and ill-defined although aiming at a 
 certain precision (there comes in the element of 
 automatism). Such is probably the condition of 
 an amoeba of one of those tiny lumps of proto- 
 plasmic jelly you can see with the microscope in 
 a drop of water. When anything that can be 
 turned into food floats by, the amoeba throws out 
 in various directions protoplasmic filaments 
 
no HUXLEY MEMORIAL LECTURES 
 
 which draw the substance towards it. These 
 pseudopodia are temporary organs, ill-defined 
 (there comes in the element of mechanism), but 
 everything seems to happen as if there were at 
 least a rudiment of intention on the part of the 
 little organism, a certain choice of appropriate 
 movements. 
 
 It appears, therefore, as if from the top to the 
 bottom of the animal scale there is present 
 (although the lower we go, the more vaguely it 
 is seen) the faculty of choice, and more particu- 
 larly the choice of action, of combined move- 
 ments, in response to stimulation arising from 
 without. This is what we find in pursuing our 
 second line of facts. Now, observe that the point 
 we come out at is pretty close to that to which the 
 first line led us. We said, you will remember, 
 that the function of consciousness seemed 
 primarily to retain the past and to anticipate the 
 future. That is quite natural if its function is to 
 preside over actions which are chosen. For 
 choice implies that one thinks of what is to be, 
 of the immediate future, with a view to creating 
 this future to some extent; and that cannot be 
 done save by profiting from past experience by 
 retaining the past in order to project it within the 
 future. 
 
 But all this gives no answer as yet to the ques- 
 tion we put : Does consciousness cover the whole 
 domain of life? and if it does not extend every- 
 where, where does it stop? 
 
LIFE AND CONSCIOUSNESS in 
 
 We have not yet the answer to this question, it 
 is true; but we are getting near it. For if con- 
 sciousness implies choice, and choice amongst 
 various possible actions, consciousness will not 
 be found presumably in organisms that do not 
 possess the power of free action the power, con- 
 sequently, to choose between several actions. In 
 very truth, I believe no living organism is abso- 
 lutely without the faculty of performing actions 
 and moving spontaneously; for we see that even 
 in the vegetable world, where the organism is for 
 the most part fixed to the ground, the faculty of 
 motion is asleep rather than absent altogether. 
 Sometimes it wakes up, just when it is likely to 
 be useful. Therefore, in principle, this faculty 
 of spontaneous motion probably exists in every 
 living thing; but, in actual fact, many organisms 
 have given it up, as, for example, the numerous 
 animals living as parasites on other organisms, 
 and thus able to get their food on the spot, and 
 again, almost the entire vegetable kingdom. It 
 seems probable, therefore, and this is my last 
 word on the point, that consciousness is in prin- 
 ciple present in all living matter, but that it is 
 dormant or atrophied wherever such matter re- 
 nounces spontaneous activity, and on the contrary 
 that it becomes more intense, more complex, more 
 complete, just where living matter trends most in 
 the direction of activity and movement. Observe 
 that this is a point we can experience in ourselves. 
 Precisely as our actions cease to be spontaneous 
 
ii2 HUXLEY MEMORIAL LECTURES 
 
 and become automatic, consciousness is with- 
 drawn from them; when we learn a new physical 
 exercise, for example, and have to decide on each 
 of our motions and choose that which is 
 appropriate, we have distinct consciousness of 
 each. As we get used to the exercise and it be- 
 comes automatic, consciousness fades away. 
 Again, when is our consciousness most acute, 
 most intensely alive? Is it not, above all, at 
 those times of internal crisis when we are hesi- 
 tating between several possible actions, several 
 lines of conduct that are equally possible ? Con- 
 sciousness in each of us, then, seems to express 
 the amount of choice, or, if you will, of creation, 
 at our disposal for movements and activity. 
 Analogy authorises us to infer that it is the same 
 in the whole of the organised world. 
 
 Let us consider living matter, then, under its 
 simplest form, as it may have been in the begin- 
 ning : a simple mass of protoplasmic jelly like 
 that of an amoeba. This mass can change its 
 shape at will it is therefore vaguely conscious. 
 Now, in order to develop and evolve, two courses 
 are open to it. Either it may follow the path 
 leading towards movement, action action grow- 
 ing more and more complex, more and more 
 deliberate and free as time goes on : this means 
 adventure and risk, but means also a conscious- 
 ness more and more wide awake and luminous. 
 Or, on the contrary, giving up the faculty of 
 movement and choice that it possesses, even 
 
LIFE AND CONSCIOUSNESS 113 
 
 though of course in very feeble degree, it may 
 decide to fix itself just where it finds suitable con- 
 ditions of life which will do away with the neces- 
 sity of going to seek the materials it requires : 
 that means an assured and tranquil life, a hum- 
 drum sort of existence, but it involves the drowsi- 
 ness which dogs our inactivity, the slumber of 
 consciousness.* The former direction corre- 
 sponds in the main to the line of animal develop- 
 ment (I say in the main, because many species of 
 animals give up their mobility, and thus probably 
 also their consciousness); the latter, in the main, 
 is proper to vegetables ; again I say " in the 
 main," since the faculty of moving, and probably 
 therefore also of consciousness, may occasionally 
 reawaken in vegetable life. 
 
 Now, if we consider from this standpoint the 
 entrance of life in the world, this entrance will 
 appear to us like the introduction, into the world, 
 of something that encroaches upon inert matter. 
 In the non-living unorganised world, if this were 
 left alone, necessity would sit enthroned. In 
 determinate conditions inert matter reacts in a 
 determinate way; in the inanimate world nothing 
 is unforeseeable, and if our science were suf- 
 ficiently advanced we should be able to foretell 
 what will happen there, precisely as we can fore- 
 tell the eclipses of the sun and moon. In short, 
 inert matter is subject to mathematical necessity. 
 
 * See on this subject : Cope, The Origin of the Fittest, 
 1887, p. 76. 
 
ii4 HUXLEY MEMORIAL LECTURES 
 
 But, with the coming of life, we see the appear- 
 ance of indetermination. A living being, no 
 matter how simple, is a reservoir of indetermina- 
 tion and unforeseeability, a reservoir of possible 
 actions or, in a word, of choice. And in it, too, 
 we find that faculty of imagining future eventuali- 
 ties (or, speaking more generally, of anticipating 
 the future), and at the same time of storing up 
 the past for that purpose, which is the faculty of 
 consciousness. 
 
 If this be so, consciousness and matter would 
 appear to be antagonistic forces, which, neverthe- 
 less, come to a mutual understanding and manage 
 somehow to get on together. They are antagon- 
 istic in this, that matter is theoretically the realm 
 of fatality, while consciousness is essentially that 
 of liberty ; and yet life, which is nothing but con- 
 sciousness using matter for its purposes, succeeds 
 in reconciling them. Life, therefore, must be 
 something which avails itself of a certain elasticity 
 in matter slight in amount as this probably is 
 and turns it to the profit of liberty by stealing into 
 whatever infinitesimal fraction of indetermination 
 that inert matter may present. Now I believe 
 that this twofold conclusion is precisely what we 
 shall come to after following certain other lines 
 of facts, and that in following these lines we may, 
 moreover, catch a glimpse at once of how con- 
 sciousness finds matter an obstacle, and how, not- 
 withstanding, it succeeds in making use of it. I 
 will begin with the last point. 
 
LIFE AND CONSCIOUSNESS 115 
 
 If we ask ourselves how a conscious animal 
 succeeds in obtaining from matter that is to say, 
 from its body the execution of movements on 
 which it has decided, we find that its method con- 
 sists in making use of special substances which 
 might be called " explosives." These substances 
 are the foodstuffs, more particularly those called 
 ternary, the essential elements of which are 
 carbon, oxygen and hydrogen. In these food- 
 stuffs is stored up a considerable amount of 
 potential energy, ready to burst out suddenly, 
 like the energy stored up in gunpowder. This 
 energy has been slowly, gradually, borrowed from 
 the sun by plants ; and the animal which feeds on 
 a plant, or on another animal that has fed on a 
 plant, or on an animal that has fed on another 
 animal that has fed on a plant, etc., thus passes 
 into his own body an explosive made by life 
 through a storage of solar energy : when this 
 animal performs voluntary movements, it does so 
 by simply producing the infinitesimal spark which 
 sets off the explosive by, as it were, just brush- 
 ing the trigger of a pistol and thus setting free a 
 considerable force in the direction chosen at will. 
 Now if, in the beginning, the first living beings 
 swayed between animal and vegetable conditions, 
 sharing at once in both one and the other, it is 
 because life at its origin had to perform the 
 double work of making the explosive and turning 
 it to account. In proportion as plants and 
 animals differentiated, life split up into two king- 
 
n6 HUXLEY MEMORIAL LECTURES 
 
 doms, of which one, the less concerned with 
 movement, was more concerned with making the 
 explosive, whilst the other confined itself to mak- 
 ing- use of it. Nevertheless, the essence of life 
 seems to be to secure that matter, by a process 
 necessarily very slow and difficult, should store 
 up energy ready for life afterwards to expend 
 this energy suddenly in free movements. Now, 
 what precisely would a free cause do a cause 
 incapable of forcing the necessity of matter, or 
 only able to force it to an infinitesimal extent, and 
 which, nevertheless, were desirous of producing 
 movements of increasingly greater power? It 
 would act in precisely this way. It would arrange 
 so as merely to have to press, as it were, the 
 trigger of a pistol in which there would be no 
 friction, or to furnish an infinitesimal spark, profit- 
 ing by an energy that it would have gradually 
 accumulated by turning every movement to 
 account. 
 
 But we arrive at the same conclusion if we re- 
 gard the living and conscious being along a dif- 
 ferent line of facts not on the side of " choice," 
 but on that of " memory." By what sign do we 
 recognise in current experience a " man of 
 action," I mean a man able to impress his mark 
 on the events, large or small, amongst which he 
 evolves ? Surely by the fact that he can take in, 
 at a single glance, a great number of things, 
 especially a great number of previous happen- 
 ings. He seizes all these in a single perception 
 
LIFE AND CONSCIOUSNESS 117 
 
 which instructs him for the action he prepares. 
 The more successive events he seizes in this 
 single glance, the better he succeeds in domin- 
 ating them. Now, if we consider consciousness 
 confronted with matter, we find that it is charac- 
 terised by just this fact, that in an interval which 
 for it is infinitely short, and which constitutes one 
 of our " instants," it seizes under an indivisible 
 form millions and billions of events that succeed 
 each other in inert matter. Yes, that indivisible 
 sensation of light which I have at this moment, if 
 I open my eyes for a single instant, is the con- 
 densation of an immensely long history unrolling 
 itself in the world of matter : there are, in that 
 single instant, billions of successive vibrations 
 that is to say, a series of events such that, if I 
 wished to count them even with the utmost 
 rapidity, it would require thousands and thou- 
 sands of years for the enumeration. It is this 
 immense history that I seize all at once under the 
 pictorial form of a very brief sensation of light. 
 And we could say just the same of all our other 
 sensations. Sensation, which is the point at 
 which consciousness touches matter, is, then, the 
 condensation, in the duration peculiar to this con- 
 sciousness, of a history which in itself, in the 
 world of matter, is something infinitely diluted, 
 and which occupies enormous periods of what 
 might be called the duration of things. So, 
 looked at from the side of sensation, conscious- 
 ness gives us the same impression as it did just 
 
n8 HUXLEY MEMORIAL LECTURES 
 
 now from the side of movement. Consciousness 
 behaves just like a power entering matter in order 
 to draw the highest possible advantage from the 
 elasticity it finds therein, to take possession of 
 matter from the side of movement as well as from 
 that of sensation : from the side of movement, by 
 an explosive action setting free, in a flash, energy 
 drawn from matter through years and years, and 
 directing this energy in a chosen way; from the 
 side of sensation, by an effort of concentration 
 which seizes as a whole, in one moment, billions 
 of events happening in things, and thus allows 
 us to control them. 
 
 Thus all the lines of facts we follow seem to 
 converge on the same point, a point at which we 
 seem to see the following image arise : on the one 
 hand, matter subject to necessity, a kind of 
 immense machine, without memory, or at least 
 having only just sufficient memory to bridge the 
 interval between one instant and the next, each 
 of the states of the material world being capable, 
 or almost so, of mathematical deduction from the 
 preceding state, and consequently adding nothing 
 thereto; on the other hand, consciousness that 
 is to say, on the contrary, a force essentially free 
 and essentially memory, a force whose very 
 character is to pile up the past on the past, like a 
 rolling snowball, and at every instant of duration 
 to organise with this past something new which is 
 a real creation. That these two forms of exist- 
 ence, matter and consciousness, have indeed a 
 
LIFE AND CONSCIOUSNESS 119 
 
 common origin, seems to me probable. I believe 
 that the first is a reversal of the second, that while 
 consciousness is action that continually creates 
 and multiplies, matter is action which continually 
 unmakes itself and wears out; and I believe also 
 that neither the matter constituting a world nor 
 the consciousness which utilises this matter can 
 be explained by themselves, and that there is a 
 common source of both this matter and this con- 
 sciousness. But I cannot now enter deeply into 
 this question. Let it suffice to say that I see in 
 the whole evolution of life on our planet an effort 
 of this essentially creative force to arrive, by 
 traversing matter, at something which is only 
 realised in man, and which, moreover, even in 
 man, is realised only imperfectly. 
 
 There is no need to recall here all the facts 
 which, since Lamarck in France and Darwin in 
 England, have been adduced to confirm the idea 
 of an evolution of species, that is to say, of the 
 generation of some species from others, com- 
 mencing by forms probably of infinite simplicity. 
 I think that on this head it is impossible to dis- 
 pute the results accepted to-day by practically all 
 biologists. And it is impossible not to admire 
 the enormous amount of effort expended during 
 the last fifty years to show the part played in the 
 evolution of living beings by the necessity these 
 labour under to adapt themselves to their 
 environment. But this necessity of adaptation 
 explains, to my thinking, the arrests of life at 
 
120 HUXLEY MEMORIAL LECTURES 
 
 such or such determinate forms much more than 
 the movement through which life becomes more 
 complex and raises itself towards greater and 
 greater efficiency. A very simple rudimentary 
 being is as well adapted as a man to its environ- 
 ment, since it succeeds in living in it : why, then, 
 if adaptation explains everything, has life gone 
 on complicating itself, and, moreover, compli- 
 cating itself more and more delicately and 
 dangerously? Molluscs such as the Lingulae, 
 existing at the present time, existed also in the 
 remotest ages of the palaeozoic era. Why did 
 life go any further ? Why, if there is not behind 
 life an impulse, an immense impulse to climb 
 higher and higher, to run greater and greater risks 
 in order to arrive at greater and greater efficiency ? 
 I think it is hard to survey the whole of the 
 evolution of life without the impression that this 
 impulse is a reality. The error is to believe that 
 this impulse has projected living matter in a 
 single direction, that species are classified along a 
 single scale, that everything has gone on smoothly 
 and without let or hindrance. It is, on the con- 
 trary, obvious that the force I speak of has found 
 resistances in the matter it had to make use of; 
 that it has been obliged to split up I mean to 
 share along lines of different evolution the dif- 
 ferent tendencies it carried ; that on each of these 
 lines there is a crowd of failures, of deviations, 
 of reversions ; that many of these lines of evolu- 
 tion have not been able to go on very far; that 
 
LIFE AND CONSCIOUSNESS 121 
 
 two alone seem to have led to a certain success, 
 partial only on one, but relatively complete on 
 the other. These two lines are those of the 
 Arthropods and the Vertebrates. At the end of 
 the first we find instinct in its most marvellous 
 forms; at the end of the second, the human 
 intellect. It seems then, indeed, as if the force I 
 speak of were a force that contained in itself, at 
 least potentially, and interfused, the two forms of 
 consciousness that we call instinct and intelli- 
 gence. 
 
 Things seem to happen as if an immense cur- 
 rent of consciousness (a consciousness which 
 includes a multitude of potentialities all crowd- 
 ing on and hindering each other) had traversed 
 matter in order to entice it to organisation and 
 make of this matter, which is necessity itself, an 
 instrument of liberty. But it has scarcely 
 escaped being itself ensnared. Matter, which is 
 essentially automatism and necessity, enfolds the 
 consciousness which seeks to entice it, converts it 
 to its own automatism, and lulls it into its own 
 unconsciousness. On certain lines of evolution, 
 as, for example, in the vegetable kingdom, this 
 automatism and unconsciousness have become 
 the rule, and the liberty of the evolutive force 
 cannot show itself except in the creation of forms 
 which are, indeed, veritable works of art. These 
 unforeseeable forms, once created, repeat them- 
 selves automatically, and the individual has no 
 power of choice. On other lines, consciousness 
 
122 HUXLEY MEMORIAL LECTURES 
 
 succeeds in disentangling itself sufficiently for 
 the individual to have a certain latitude of choice, 
 a certain feeling, but the necessities of life are 
 there, and make of this power of choice a simple 
 auxiliary of material existence. Thus, along the 
 whole course of the evolution of life, liberty is 
 dogged by automatism, and in the long run is 
 stifled by it. With man alone the chain has been 
 broken. I cannot here enter into detail as to the 
 causes which have permitted life, by a sudden 
 leap from animal to man, to break the chain. I 
 confine myself to saying that the human brain, 
 although, seen from without, it differs little from 
 that of a highly developed animal, yet possesses 
 this remarkable feature that it can oppose to 
 every contracted habit another habit, to every 
 kind of automatism another automatism, so that 
 in man liberty succeeds in freeing itself by 
 setting necessity to fight against necessity. 
 
 I doubt that the evolution of life will ever be 
 explained by a mere combination of mechanical 
 forces. Obviously there is a vital impulse : what 
 I was just calling an impulse towards a higher 
 and higher efficiency, something which ever seeks 
 to transcend itself, to extract from itself more 
 than there is in a word, to create. Now, a force 
 which draws from itself more than it contains, 
 which gives more than it has, is precisely what is 
 called a spiritual force : in fact, I do not see how 
 otherwise spirit is to be defined. But, on the 
 other hand, we are wrong when we fail to take 
 
LIFE AND CONSCIOUSNESS 123 
 
 into account, in the explanation of the organic 
 world, the obstacles of every kind which this force 
 encounters. The spectacle of the evolution of 
 life from its very beginning down to man suggests 
 to us the image of a current of consciousness 
 which flows down into matter as into a tunnel, 
 which endeavours to advance, which makes efforts 
 on every side, thus digging galleries most of 
 which are stopped by a rock that is too hard, but 
 which, in one direction at least, prove possible to 
 follow to the end and break out into the light once 
 more. This direction is the line of evolutipn 
 resulting in man. Now, what has been gained 
 by forcing this tunnel, and why did life start on 
 the undertaking ? Here, again, new lines of facts 
 might lead us to a plausible conclusion, one that 
 may become more and more probable. But I 
 have so little time, and it would be necessary to 
 enter into such great detail on the mechanism of 
 psychical facts above all, on the physio-psycho- 
 logical relation that I can now only formulate 
 briefly my conclusions. When, setting one 
 against the other, we examine consciousness and 
 matter in their mutual reactions, we have the 
 impression that matter plays at first, in relation to 
 consciousness, the part of an instrument that cuts 
 it up in order to bring about a greater precision. 
 A thought only becomes precise when it is divided 
 into words, that is, if it can be so divided; an 
 orator does not quite know what he is going to 
 say, and what he means to say, until he has taken 
 
i2 4 HUXLEY MEMORIAL LECTURES 
 
 a sheet of paper and set forth clearly in separate 
 phrases, placed side by side, what in his mind 
 was given in a state of mutual interpenetration. 
 Thus first does matter separate that which was 
 blended, and distinguish what was confused. 
 But moreover, and above all, matter is what pro- 
 vokes effort and renders it possible. The thought 
 which is only thought, the work of art which is 
 only in the conceptual state, the poem which is 
 only a dream, costs as yet no effort : what re- 
 quires an effort is the material realisation of the 
 poem in words, of the artistic conception in a 
 statue or a picture. This effort is painful, it may 
 be very painful ; and yet, whilst making it, we 
 feel that it is as precious as, and perhaps more 
 precious than, the work it results in, because, 
 thanks to it, we have drawn from ourselves not 
 only all that was there, but more than was there : 
 we have raised ourselves above ourselves. 
 
 Now, this effort would not have been put forth 
 without matter, which, by the unique nature of the 
 resistance it opposes and the unique nature of the 
 docility to which it can be brought, plays at one 
 and the same time the role of obstacle and 
 stimulus, causes us to feel our force and also to 
 succeed in intensifying it. 
 
 Philosophers who have speculated on the 
 significance of life and the destiny of man have 
 not sufficiently remarked that Nature has taken 
 pains to give us notice every time this destiny is 
 accomplished; she has set up a sign which 
 
LIFE AND CONSCIOUSNESS 125 
 
 apprises us every time our activity is in full ex- 
 pansion; this sign is joy. I say joy; I do not 
 say pleasure. Pleasure, in point of fact, is no 
 more than an instrument contrived by Nature to 
 obtain from the individual the preservation and 
 the propagation of life ; it gives us no information 
 concerning the direction in which life is flung 
 forward. True joy, on the contrary, is always 
 an emphatic signal of the triumph of life. Now, 
 if we follow this new line of facts, we find that 
 wherever joy is, creation has been, and that the 
 richer the creation the deeper the joy. The 
 mother looking upon her child is joyous because 
 she has the consciousness of having created it, 
 physically and morally. A man who succeeds in 
 his enterprise for example, a captain of indus- 
 try whose business is prospering is he joyous 
 solely on account of the money he is winning and 
 the notoriety he has acquired? Doubtless these 
 elements count for much in the satisfaction he 
 feels; but they bring him pleasures rather than 
 joy, and whatever true joy he tastes belongs 
 essentially to the consciousness he has of having 
 established an enterprise which marches on, of 
 having created something that goes ahead. Con- 
 sider exceptional joys like those of the great 
 artist who has produced a masterpiece, of the 
 scientific man who has made a discovery or inven- 
 tion. We sometimes say they have worked for 
 glory and derive their greatest satisfaction from 
 the applause of mankind. Profound mistake ! 
 
126 HUXLEY MEMORIAL LECTURES 
 
 We care for praise in the exact measure in which 
 we feel not sure of having succeeded ; it is because 
 we want to be reassured as to our own value and 
 as to the value of what we have done that we seek 
 praise and prize glory. But he who is certain, 
 absolutely certain, that he has brought a living 
 work to the birth, cares no more for praise and 
 feels himself beyond glory, because there is no 
 greater joy than that of feeling oneself a creator. 
 If, then, in every province, the triumph of life is 
 expressed by creation, ought we not to think that 
 the ultimate reason of human life is a creation 
 which, in distinction from that of the artist or man 
 of science, can be pursued at every moment and 
 by all men alike ; I mean the creation of self by 
 self, the continual enrichment of personality by 
 elements which it does not draw from outside, but 
 causes to spring forth from itself? 
 
 May we not therefore suppose that the passage 
 of consciousness through matter is destined to 
 bring to precision, in the form of distinct per- 
 sonalities, tendencies or potentialities which at 
 first were mingled, and also to permit these per- 
 sonalities to test their force whilst at the same 
 time increasing it by an effort of self-creation? 
 On the other hand, when we see that conscious- 
 ness, whilst being at once creation and choice, is 
 also memory, that one of its essential functions is 
 to accumulate and preserve the past, that very 
 probably (I lack time to attempt the demonstra- 
 tion of this point) the brain is an instrument of 
 
LIFE AND CONSCIOUSNESS 127 
 
 forgetfulness as much as one of remembrance, 
 and that in pure consciousness nothing of the past 
 is lost, the whole life of a conscious personality 
 being an indivisible continuity, are we not led to 
 suppose that the effort continues beyond, and that 
 in this passage of consciousness through matter 
 (the passage which at the tunnel's exit gives dis- 
 tinct personalities) consciousness is tempered like 
 steel, and tests itself by clearly constituting per- 
 sonalities and preparing them, by the very effort 
 which each of them is called upon to make, for a 
 higher form of existence? If we admit that with 
 man consciousness has finally left the tunnel, that 
 everywhere else consciousness has remained im- 
 prisoned, that every other species corresponds to 
 the arrest of something which in man succeeded 
 in overcoming resistance and in expanding almost 
 freely, thus displaying itself in true personalities 
 capable of remembering all and willing all and 
 controlling their past and their future, we shall 
 have no repugnance in admitting that in many, 
 though perhaps in man alone, consciousness pur- 
 sues its path beyond this earthly life. 
 
 This is as much as to say that, in my opinion, 
 the aspirations of our moral nature are not in the 
 least contradicted by positive science. On this, 
 as on many other points, I quite agree with the 
 opinion expressed by Sir Oliver Lodge in many 
 of his works, and especially in his admirable book 
 on Life and Matter. How could there be dis- 
 harmony between our intuitions and our science, 
 
128 HUXLEY MEMORIAL LECTURES 
 
 how especially could our science make us re- 
 nounce our intuitions, if these intuitions are some- 
 thing like instinct an instinct conscious, refined, 
 spiritualised and if instinct is still nearer life 
 than intellect and science? Intuition and intel- 
 lect do not oppose each other, save where intuition 
 refuses to become more precise by coming into 
 touch with facts scientifically studied, and where 
 intellect, instead of confining itself to science 
 proper (that is, to what can be inferred from facts 
 or proved by reasoning), combines with this an 
 unconscious and inconsistent metaphysic which 
 in vain lays claim to scientific pretensions. The 
 future seems to belong to a philosophy which will 
 take into account the whole of what is given : 1 
 shall have attained the object I proposed if I have 
 succeeded in indicating to you, however vaguely, 
 the direction in which such a philosophy would 
 lead us. 
 
 HENRI BERGSON. 
 
 PARIS. 
 
129 
 
 PLEOCHROIC HALOES.* 
 
 By Prof. John foly, F.R.S. 
 
 It is now well established that a helium atom 
 is expelled from certain of the radioactive 
 elements at the moment of transformation. The 
 helium atom or alpha ray leaves the transforming 
 atom with a velocity which varies in the different 
 radioactive elements, but which is always very 
 great, attaining as much as 2 x io 9 cms. per 
 second; a velocity which, if unchecked, would 
 carry the atom round the earth in less than two 
 seconds. The alpha ray carries a positive charge 
 of double the ionic amount. 
 
 When an alpha ray is discharged from the 
 transforming element into a gaseous medium its 
 velocity is rapidly checked and its energy 
 absorbed. A certain amount of energy is thus 
 transferred from the transforming atom to the 
 gas. We recognise this energy in the gas by the 
 altered properties of the latter ; chiefly by the fact 
 that it becomes a conductor of electricity. The 
 mechanism by which this change is effected is in 
 part known. The atoms of the gas, which appear 
 to be freely penetrated by the alpha ray, are so 
 
 * Being the Huxley Lecture, delivered at the University 
 of Birmingham on October 3Oth, 1912. 
 
130 HUXLEY MEMORIAL LECTURES 
 
 far dismembered as to yield charged electrons or 
 ions; the atoms remaining charged with an equal 
 and opposite charge. Such a medium of free 
 electric charges becomes a conductor of electricity 
 by convection when an electromotive force is 
 applied. The gas also acquires other properties 
 in virtue of its ionisation. Under certain con- 
 ditions it may acquire chemical activity and new 
 combinations may be formed or existing ones 
 broken up. When its initial velocity is expended 
 the helium atom gives up its properties as an 
 alpha ray and thenceforth remains possessed of 
 the ordinary varying velocity of thermal agitation. 
 Bragg and Kleeman and others have investigated 
 the career of the alpha ray when its path or range 
 lies in a gas at ordinary or obtainable conditions 
 of pressure and temperature. We will review 
 some of the facts ascertained. 
 
 The range or distance traversed in a gas at 
 ordinary pressures is a few centimetres. The 
 following table, compiled by Geiger, gives the 
 range in air at the temperature of 15 C. : 
 
 cms. 
 
 Uranium i 2.50 
 
 Uranium 2 ... 2.90 
 
 Ionium ... ... ... ... ... 3- 
 
 Radium 3-3 
 
 Ra Emanation 4-*6 
 
 Radium A 4-75 
 
 Radium C 6.94 
 
 Radium F 3-77 
 
PLEOCHROIC HALOES 131 
 
 cms. 
 
 Thorium 2.72 
 
 Radiothorium 3.87 
 
 Thorium X 4.30 
 
 Th Emanation 5.00 
 
 Thorium A ... 5.70 
 
 Thorium C a 4.80 
 
 Thorium C s 8.60 
 
 cms. 
 Radioactinium ... ... ... ... 4.60 
 
 Actinium X 4.40 
 
 Act Emanation 5.70 
 
 Actinium A 6.50 
 
 Actinium C ... ... ... ... 5.40 
 
 It will be seen that the ray of greatest range is 
 that proceeding from thorium C 2 > which reaches 
 a distance of 8*6 cms. In the uranium family the 
 fastest ray is that of radium C. It attains 6*94. 
 cms. There is thus an appreciable difference 
 between the ultimate distances traversed by the 
 most energetic rays of the two families. The 
 shortest ranges are those of uranium i and 2. 
 
 The ionisation effected by these rays is by no 
 means uniform along the path of the ray. By 
 examining the conductivity of the gas at different 
 points along the path of the ray, the ionisation 
 at these points may be determined. At the limits 
 of the range the ionisation ceases. In this man- 
 ner the range is, in fact, determined. The dotted 
 curve (Fig. i) depicts the recent investigation of 
 the ionisation effected by a sheaf of parallel rays 
 of radium C in air, as determined by Geiger. 
 
132 HUXLEY MEMORIAL LECTURES 
 
 The range is laid out horizontally in centimetres. 
 The numbers of ions are laid out vertically. The 
 remarkable nature of the results will be at once 
 apparent. We should have expected that the ray 
 at the beginning of its path, when its velocity and 
 kinetic energy were greatest, would have been 
 more effective than towards the end of its range 
 when its energy had almost run out. But the 
 curve shows that it is just the other way. The 
 lagging ray, about to resign its ionising proper- 
 ties, becomes a much more efficient ioniser than 
 it was at first. The maximum efficiency is, how- 
 ever, in the case of a bundle of parallel rays, not 
 quite at the end of the range, but about half a 
 centimetre from it. The increase to the maxi- 
 mum is rapid, the fall from the maximum to noth- 
 ing is much more rapid. 
 
 It can be shown that the ionisation effected 
 anywhere along the path of the ray is inversely 
 proportional to the velocity of the ray at that 
 point. But this evidently does not apply to the 
 last 5 or 10 mms. of the range where the rate of 
 ionisation and of the speed of the ray change 
 most rapidly. To what are the changing proper- 
 ties of the rays near the end o~ r ,.eir path to be 
 ascribed? It is only recently that this matter 
 has been elucidated. 
 
 When the alpha ray has sufficiently slowed 
 down, its power of passing right through atoms, 
 without appreciably experiencing any effects from 
 them, diminishes. The opposing atoms begin to 
 
PLEOCHROIC HALOES 133 
 
 exert an influence on the path of the ray, deflect- 
 ing it a little. The heavier atoms will deflect it 
 most. This effect has been very successfully in- 
 vestigated by Geiger. It is known as " scatter- 
 ing." The angle of scattering increases rapidly 
 with the decrease of velocity. Now the effect of 
 the scattering will be to cause some of the rays 
 to complete their ranges or, more accurately, to 
 leave their direct line of advance a little sooner 
 than others. In the beautiful experiments of 
 C. T. R. Wilson we are enabled to obtain ocular 
 demonstration of the scattering. The photograph 
 (Fig. 2), which I owe to the kindness of Mr. 
 Wilson, shows the deflection of the ray towards 
 the end of its path. In this case the path of the 
 ray has been rendered visible by the condensation 
 of water particles under the influence of the 
 ionisation; the atmosphere in which the ray 
 travels being in a state of supersaturation with 
 water vapour at the instant of the passage of the 
 ray. It is evident that if we were observing the 
 ionisation along a sheaf of parallel rays, all start- 
 ing with equal velocity, the effect of the bending 
 of some of the rays near the end of their range 
 must be to cause a decrease in the aggregate 
 ionisation near the very end of the ultimate range. 
 For, in fact, some of the rays complete their work 
 of ionising at points in the gas before the end is 
 reached. This is the cause, or at least an 
 important contributory cause, of the decline in 
 the ionisation near the end of the range, when the 
 
134 HUXLEY MEMORIAL LECTURES 
 
 effects of a bundle of rays are being observed. 
 The explanation does not suggest that the ion- 
 ising power of any one ray is actually diminished 
 before it finally ceases to be an alpha ray. 
 
 The full line in Fig. i gives the ionisation 
 curve which it may be expected would be struck 
 out by a single alpha ray. In it the ionisation 
 goes on increasing till it abruptly ceases alto- 
 gether, with the entire loss of the initial kinetic 
 energy of the particle. 
 
 A highly remarkable fact was found out by 
 Bragg. The effect of the atom traversed by the 
 ray to check the velocity of the ray is independent 
 of the physical and chemical condition of the 
 atom. He measured the " stopping power " of 
 a medium by the distance the ray can penetrate 
 into it compared with the distance to which it can 
 penetrate in air. The less the ratio the greater 
 the stopping power. The stopping power of a 
 substance is proportional to the square root of its 
 atomic weight. The stopping power of an atom 
 is not altered if it is in chemical union with 
 another atom. The atomic weight is the one 
 quality of importance. The physical state, 
 whether the element is in the solid, liquid or 
 gaseous state, is unimportant. And when we 
 deal with molecules the stopping power is simply 
 proportional to the sum of the square roots of the 
 atomic weights of the atoms entering into the 
 molecule. This is the " additive law," and it 
 obviously enables us to calculate what the range 
 
PLEOCHROIC HALOES 135 
 
 in any substance of known chemical composition 
 and density will be, compared with its range in 
 air. 
 
 This is of special importance in connection 
 with phenomena we have presently to consider. 
 It means that, knowing- the chemical composition 
 and density of any medium whatsoever, solid, 
 liquid or gaseous, we can calculate accurately the 
 distance to which any particular alpha ray will 
 penetrate. Nor have the temperature and pres- 
 sure to which the medium is subjected any influ- 
 ence save in so far as they may affect the prox- 
 imity of one atom to another. The retardation 
 of the alpha ray in the atom is not affected. 
 
 This valuable additive law cannot, however, in 
 strictness be applied to the amount of ionisation 
 attending the ray. The form of the molecule, or 
 more generally its volume, may have an influence 
 upon this. Bragg draws the conclusion, from this 
 fact as well as from the notable increase of ionisa- 
 tion with loss of speed, that the ionisation is 
 dependent upon the time the ray spends in the 
 molecule. The energy of the ray is, indeed, 
 found to be less efficient in producing ionisation 
 in the smaller atoms. 
 
 Before leaving our review of the general laws 
 governing the passage of alpha rays through 
 matter, a point of interest must be referred to. 
 We have hitherto spoken in general terms of the 
 fact that ionisation attends the passage of the 
 ray. We have said nothing as to the nature of 
 
136 HUXLEY MEMORIAL 'LECTURES 
 
 the ionisation so produced. But in point of fact 
 the ionisation due to an alpha ray is sui generis. 
 A glance at one of Wilson's photographs (Fig. 2) 
 illustrates this. The white streak of water par- 
 ticles marks the path of the ray. The ions pro- 
 duced are evidently closely crowded along the 
 track of the ray. They have been called into 
 existence in a very minute instant of time. Now 
 we know that ions of opposite sign if left to them- 
 selves recombine. The rate of recombination 
 depends upon the product of the number of each 
 sign present in unit volume. Here the numbers 
 are very great and the volume very small. The 
 ionic density is therefore high, and recombination 
 very rapidly removes the ions after they are 
 formed. We see here a peculiarity of the ionisa- 
 tion effected by alpha rays. It is linear in dis- 
 tribution and very local. Much of the ionisation 
 in gases is again undone by recombination before 
 diffusion leads to the separation of the ions. This 
 " initial recombination " is greatest towards the 
 end of the path of the ray where the ionisation is 
 a maximum. Here it may be so effective that 
 the form of the curve is completely lost unless a 
 very large electromotive force is used to separate 
 the ions when the ionisation is being investigated. 
 We have now reviewed recent work at suffi- 
 cient length to understand something of the 
 nature of the most important advance ever made 
 in our knowledge of the atom. Let us glance 
 briefly at what we have learned. The radioactive 
 
PLEOCHROIC HALOES 137 
 
 atom in sinking to a lower atomic weight casts out 
 with enormous velocity an atom of helium. It 
 thus loses a definite portion of its mass and of its 
 energy. Helium which is chemically one of the 
 most inert of the elements, is, when possessed of 
 such great kinetic energy, able to penetrate and 
 ionise the atoms which it meets in its path. It 
 spends its energy in the act of ionising them, 
 coming to rest, when it moves in air, in a few 
 centimetres. Its particular initial velocity de- 
 pends upon which of the radioactive elements has 
 given rise to it. The length of its path is there- 
 fore different according to the radioactive element 
 from which it proceeds. The retardation which 
 it experiences in its path depends entirely upon 
 the atomic weight of the atoms which it traverses. 
 As it advances in its path its effectiveness in 
 ionising the atom rapidly increases and attains a 
 very marked maximum. In a gas the ions pro- 
 duced being much crowded together recombine 
 rapidly; so rapidly that the actual ionisation may 
 be quite concealed unless a sufficiently strong 
 electric force is applied to separate them. Such 
 is a brief summary of the climax of radioactive 
 discovery : the birth, life and death of the alpha 
 ray. Its advent into Science has altered funda- 
 mentally our conception of matter. It is fraught 
 with momentous bearings upon Geological 
 Science. How the work of the alpha ray is some- 
 times recorded visibly in the rocks and what we 
 may learn from that record I propose now to 
 bring before you. 
 
138 HUXLEY MEMORIAL LECTURES 
 
 In certain minerals, notably the brown variety 
 of mica known as biotite, the microscope reveals 
 minute circular marks occurring here and there, 
 quite irregularly. The most usual appearance is 
 that of a circular area darker in colour than the 
 surrounding mineral. The radii of these little 
 disc-shaped marks when well defined are found 
 to be remarkably uniform, in some cases four- 
 hundredths of a millimetre and in others three- 
 hundredths, about. These are the measurements 
 in biotite. In other minerals the measurements 
 are not quite the same as in biotite. Such minute 
 objects are quite invisible to the naked eye. In 
 some rocks they are very abundant, indeed they 
 may be crowded together in such numbers as to 
 darken the colour of the mineral containing them. 
 They have long been a mystery to petrologists. 
 
 Close examination shows that there is always 
 a small speck of a foreign body at the centre of 
 the circle, and it is often possible to identify the 
 nature of this central substance, small though it 
 be. Most generally it is found to be the mineral 
 zircon. Now this mineral was shown by Strutt 
 to contain radium in quantities much exceeding 
 those found in ordinary rock substances. Some 
 other mineral may occasionally form the nucleus, 
 but we never find any which is not known to be 
 specially likely to contain a radioactive substance. 
 Another circumstance we notice. The smaller 
 this central nucleus the more perfect in form is 
 the darkened circular area surrounding it. When 
 
PLEOCHROIC HALOES 139 
 
 the circle is very perfect and the central mineral 
 clearly defined at its centre we find by measure- 
 ment that the radius of the darkened area is 
 generally 0*033 mm. It may sometimes be 0*040 
 mm. These are always the measurements in 
 biotite. In other minerals the radii are a little 
 different. 
 
 We see in the photograph (Fig. 3), much magni- 
 fied, a halo contained in biotite. We are looking 
 at a region in a rock section, the rock being 
 ground down to such a thickness that light freely 
 passes through it. The biotite is in the centre of 
 the field. Quartz and felspar surround it. The 
 rock is a granite. The biotite is not all one 
 crystal. Two crystals, mutually inclined, are cut 
 across. The halo extends across both crystals, 
 but owing to the fact that polarised light is used 
 in taking the photograph it appears darker in one 
 crystal than in the other. We see the zircon 
 which composes the nucleus. The fine lineated 
 appearance of the biotite is due to the cleavage 
 of that mineral, which is cut across in the section. 
 
 The question arises whether the darkened area 
 surrounding the zircon may not be due to the in- 
 fluence of the radioactive substances contained in 
 the zircon. The extraordinary uniformity of the 
 radial measurements of perfectly formed haloes 
 (to use the name by which they have long been 
 known) suggests that they may be the result of 
 alpha radiation. For in that case, as we have 
 seen, we can at once account for the definite 
 
140 HUXLEY MEMORIAL LECTURES 
 
 radius as simply representing the range of the ray 
 in biotite. The furthest-reaching ray will define 
 the radius of the halo. In the case of the uranium 
 family this will be radium C, and in the case of 
 thorium it will be thorium C 2 . Now here we pos- 
 sess a means of at once confirming or rejecting 
 the view that the halo is a radioactive phenomenon 
 and occasioned by alpha radiation; for we can 
 calculate what the range of these rays will be in 
 biotite, availing ourselves of Bragg's additive 
 law, already referred to. When we make this 
 calculation we find that radium C just penetrates 
 0*033 mm. and thorium C 2 0*040 mm. The proof 
 is complete that we are dealing with the effects 
 of alpha rays. Observe now that not only is the 
 coincidence of measurement and calculation a 
 proof of the view that alpha radiation has occa- 
 sioned the halo, but it is a very complete verifica- 
 tion of the important fact stated by Bragg, that 
 the stopping power depends solely on the atomic 
 weight of the atoms traversed by the ray. 
 
 We have seen that our examination of the 
 rocks reveals only the two sorts of halo : the 
 radium halo and the thorium halo. This is not 
 without teaching. For why not find an actinium 
 halo ? Now Rutherford long ago suggested that 
 this element and its derivatives were probably an 
 offspring of the uranium family; a side branch, 
 as it were, in the formation of which relatively 
 few transforming atoms took part. On Ruther- 
 ford's theory then, actinium should always accom- 
 
PLEOCHROIC HALOES 141 
 
 pany uranium and radium, but in very subordinate 
 amount. The absence of actinium haloes clearly 
 supports this view. For if actinium was an inde- 
 pendent element we would be sure to find 
 actinium haloes. The difference in radius should 
 be noticeable. If, on the other hand, actinium 
 was always associated with uranium and radium, 
 then its effects would be submerged in those of 
 the much more potent effects of the uranium 
 series of elements. 
 
 It will have occurred to you already that if the 
 radioactive origin of the halo is assured, the shape 
 of a halo is not really circular, but spherical. 
 This is so. There is no such thing as a disc- 
 shaped halo. The halo is a spherical volume 
 containing the radioactive nucleus at its centre. 
 The true radius of the halo may, therefore, only 
 be measured on sections passing through the 
 nucleus. 
 
 In order to understand the mode of formation 
 of a halo we may profitably study on a diagram 
 the events which go on within the halo-sphere. 
 Such a diagram is seen in Fig. 4. It shows to 
 relatively correct scale the limiting range of all 
 the alpha-ray producing members of the uranium 
 and thorium families. We know that each mem- 
 ber of a family will exist in equilibrium amount 
 within the nucleus possessing the parent element. 
 Each alpha ray leaving the nucleus will just 
 attain its range and then cease to affect the mica. 
 Within the halo-sphere, there must be, therefore, 
 
142 HUXLEY MEMORIAL LECTURES 
 
 the accumulated effects of the influences of all the 
 rays. Each has its own sphere of influence, and 
 the spheres are all concentric. 
 
 The radii in biotite of the several spheres are 
 given in the following table : 
 
 URANIUM FAMILY. 
 
 mm. 
 
 Radium C 0.0330 
 
 Radium A 0.0224 
 
 Ra Emanation 0.0196 
 
 Radium F 0.0177 
 
 Radium 0.0156 
 
 Ionium 0.0141 
 
 Uranium i 0.0137 
 
 Uranium 2 0.0118 
 
 THORIUM FAMILY. 
 
 mm. 
 
 Thorium C 2 0.040 
 
 Thorium A 0.026 
 
 Th Emanation 0.023 
 
 Thorium C t 0.022 
 
 Thorium X 0.020 
 
 Radiothorium 0.019 
 
 Thorium 0.013 
 
 In the photograph (Fig. 5) we see a uranium 
 and a thorium halo in the same crystal of mica. 
 The mica is contained in a rock-section and is cut 
 across the clevage. The effects of thorium C 2 
 are clearly shown as a lighter border surrounding 
 the accumulated inner darkening due to the other 
 thorium rays (upper halo). The uranium halo 
 (to the right) similarly shows the effect of radium 
 C, but less distinctly. 
 
PLEOCHROIC HALOES 143 
 
 Haloes which are uniformly dark all over as 
 described above are, in point of fact, " over-ex- 
 posed " ; to borrow a familiar photographic term. 
 Haloes are found which show much very beauti- 
 ful internal detail. Too vigorous action obscures 
 this detail just as detail is lost in an over-exposed 
 photograph. We may again have " under- 
 exposed " haloes in which the action of the several 
 rays is incomplete or in which the action of certain 
 of the rays has left little if any trace. Beginning 
 at the most under-exposed haloes we find circular 
 dark marks having the radius 0*012 or 0*013 mm - 
 These haloes are due to uranium although their 
 inner darkening is doubtless aided by the passage 
 of rays which were too few to extend the darken- 
 ing beyond the vigorous effects of the two 
 uranium rays. Then we find haloes carried out 
 to the radii 0*0 1 6, 0*018 and 0*019 mm. The last 
 sometimes show very beautiful outer rings having 
 radial dimensions such as would be produced by 
 radium A and radium C. Finally we may have 
 haloes in which interior detail is lost so far out 
 as the radius due to emanation or radium A, while 
 outside this floats the ring due to radium C. Cer- 
 tain variations of these effects may occur, mark- 
 ing, apparently, different stages of exposure. 
 Figs. 6 and 7 illustrate some of these stages ; the 
 latter photograph being greatly enlarged to show 
 clearly the halo-sphere of radium A. 
 
 In most of the cases referred to above the 
 structure evidently shows the existence of con- 
 
144 HUXLEY MEMORIAL LECTURES 
 
 centric spherical shells of darkened biotite. This 
 is a very interesting fact. For it proves that in 
 the mineral the alpha ray gives rise to the same 
 increased ionisation towards the end of its range 
 as Bragg determined in the case of gases. And 
 we must conclude that the halo in every case 
 grows in this manner. A spherical shell of 
 darkened biotite is first produced and the inner 
 colouration is only effected as the more feeble 
 ionisation along the track of the ray in course of 
 ages gives rise to sufficient alteration of the 
 mineral. This more feeble ionisation is, near the 
 nucleus, enhanced in its effects by the fact that 
 there all the rays combine to increase the ionisa- 
 tion and, moreover, the several tracks are there 
 crowded by the convergency to the centre. 
 Hence the most elementary haloes seldom show 
 definite rings due to uranium, etc., but appear as 
 embryonic disc-like markings. The photographs 
 on the screen illustrate many of the phases of halo 
 development. Rutherford succeeded in making 
 a halo artificially by compressing into a capillary 
 glass tube a quantity of the emanation of radium. 
 As the emanation decayed the various derived 
 products came into existence and all the several 
 alpha rays penetrated the glass; darkening the 
 walls of the capillary out to the limit of the range 
 of radium C in glass. Fig. 8 is a magnified 
 view of the tube. The dark central part is the 
 capillary. The tubular halo surrounds it. This 
 experiment has, however, been anticipated by 
 
PLEOCHROIC HALOES 145 
 
 some scores of millions of years, for here is the 
 same effect in a biotite crystal (Fig. 9). Along 
 what are apparently tubular passages or cracks 
 in the mica, a solution, rich in radioactive sub- 
 stances, has moved ; probably during the final 
 consolidation of the granite in which the mica 
 occurs. A continuous and very regular halo has 
 developed along these conduits. A string of 
 halo-spheres may lie along such passages. We 
 must infer that solutions or gases able to establish 
 the radioactive nuclei moved along these conduits, 
 and we are entitled to ask if all the haloes in this 
 biotite are not, in this sense, of secondary origin. 
 There is, I may add, much to support such a con- 
 clusion. 
 
 It must not be thought that the under-exposed 
 halo is a recent creation. By no means. All are 
 old, appallingly old; and in the same rock all 
 are, probably, of the same, or nearly the same, 
 age. The under-exposure is simply due to a 
 lesser quantity of the radioactive elements in the 
 nucleus. They are under-exposed, in short, not 
 because of lesser duration of exposure, but be- 
 cause of insufficient action; as when in taking a 
 photograph the stop is not open enough for the 
 time of the exposure. 
 
 The halo has, so far, told us that the additive 
 law is obeyed in solid media and that the in- 
 creased ionisation attending the slowing down of 
 the ray obtaining in gases also obtains in solids ; 
 for, otherwise, the halo would not commence its 
 
i 4 6 HUXLEY MEMORIAL LECTURES 
 
 development as a spherical shell or envelope. 
 But here we learn that there is probably a certain 
 difference in the course of events attending the 
 immediate passage of the ray in the gas and in 
 the solid. In the former initial recombination 
 may obscure the intense ionisation near the end 
 of the range. We can only detect the true end 
 effects by artificially separating the ions by a 
 strong electric force. If this recombination hap- 
 pened in the mineral we should not have the 
 concentric spheres so well defined as we see them 
 to be. What, then, hinders the initial recombina- 
 tion in the solid? The answer probably is that 
 the newly formed ion is instantly used up in a 
 fresh chemical combination. Nor is it free to 
 change its place as in the gas. There is simply a 
 new equilibrium brought about by its sudden pro- 
 duction. In this manner the conditions in the 
 complex molecule of biotite, tourmaline, etc., may 
 be quite as effective in preventing initial recom- 
 bination as the most effective electric force we 
 could apply. The final result is that we find the 
 Bragg curve reproduced most accurately in the 
 delicate shading of the rings making up the per- 
 fectly exposed halo. 
 
 That the shading of the rings reproduces the 
 form of the Bragg curve, projected, as it were, 
 upon the line of advance of the ray and repro- 
 duced in depth of shading, shows that in yet 
 another particular the alpha ray behaves much 
 the same in the solid as in the gas. A careful 
 
PLEOCHROIC HALOES 147 
 
 examination of the outer edge of the circles always 
 reveals a steep but not abrupt cessation of the 
 action of the ray. Now Geiger has investigated 
 and proved the existence of scattering of the 
 alpha ray by solids. We may, therefore, suppose 
 with much probability that there is the same scat- 
 tering within the mineral near the end of the 
 range. The heavy iron atom of the biotite is, 
 doubtless, chiefly responsible for this in biotite 
 haloes. I may observe that this shading of the 
 outer bounding surface of the sphere of action is 
 found however minute the central nucleus. In 
 the case of a nucleus of considerable size another 
 effect comes in which tends to produce an 
 enhanced shading. This will result if rays pro- 
 ceed from different depths in the nucleus. If the 
 nucleus was of the same density and atomic 
 weight as the surrounding mica, there would be 
 little effect. But its density and molecular weight 
 are generally greater, hence the retardation is 
 greater, and rays proceeding from deep in the 
 nucleus experience more retardation than those 
 which proceed from points near to the surface. 
 The distances reached by the rays in the mica 
 will vary accordingly, and so there will be a 
 gradual cessation of the effects of the rays. 
 
 The result of our study of the halo may be 
 summed up in the statement that in nearly every 
 particular we have the phenomena which have 
 been measured and observed in the gas repro- 
 duced on a minute scale in the halo. Initial re- 
 
148 HUXLEY MEMORIAL LECTURES 
 
 combination seems, however, to be absent or 
 diminished in effectiveness; probably because of 
 the new stability instantly assumed by the ionised 
 atoms. 
 
 One of the most interesting points about the 
 halo remains to be referred to. The halo is 
 always uniformly darkened all round its circum- 
 ference and is perfectly spherical. Sections, 
 whether taken in the plane of cleavage of the 
 mica or across it, show the same exactly circular 
 form, and the same radius. Of course, if there 
 was any appreciable increase of range along or 
 across the cleavage the form of the halo on the 
 section across the cleavage should be elliptical. 
 The fact that there is no measurable ellipticity is, 
 I think, one which would not on first consideration 
 be expected. 
 
 For what are the conditions attending the pas- 
 sage of the ray in a medium such as mica? 
 According to crystallographic conceptions we 
 have here an orderly arrangement of molecules, 
 the units composing the crystal being alike in 
 mass, geometrically spaced, and polarised as re- 
 gards the attractions they exert one upon another. 
 Mica, more especially, has the cleavage phe- 
 nomenon developed to a degree which transcends 
 its development in any other known substance. 
 We can cleave it and again cleave it till its flakes 
 float in the air, and we may yet go on cleaving it 
 by special means till the flakes no longer reflect 
 visible light. And not less remarkable is the 
 
PLEOCHROIC HALOES 149 
 
 uniplanar nature of its cleavage. There is little 
 cleavage in any plane but the one, although it is 
 easy to show that the molecules in the plane of 
 the flake are in orderly arrangement and are more 
 easily parted in some directions than in others. 
 In such a medium beyond all others we must look 
 with surprise upon the perfect sphere struck out 
 by the alpha rays, because it seems certain that 
 the cleavage is due to lesser attraction, and, 
 probably, further spacing of the molecules, in a 
 direction perpendicular to the cleavage. 
 
 It may turn out that the spacing of the mole- 
 cules will influence but little the average number 
 per unit distance encountered by rays moving in 
 divergent paths. If this is so we seem left to 
 conclude that in spite of its unequal and polarised 
 attractions there is equal retardation and equal 
 ionisation in the molecule in whatever direction it 
 is approached. Or, again, if the encounters in- 
 deed differ in number, then some compensating 
 effect must exist whereby a direction of lesser 
 linear density involves greater stopping power 
 in the molecule encountered, and vice versa. 
 
 The nature of the change produced by the 
 alpha rays is unknown. But the formation of the 
 halo is not, at least in its earlier stages, attended 
 by destruction of the crystallographic and optical 
 properties of the medium. The optical proper- 
 ties are unaltered in nature but increased in 
 intensity. This applies till the halo has become 
 so darkened that light is no longer transmitted 
 
150 HUXLEY MEMORIAL LECTURES 
 
 under the conditions of thickness obtaining in 
 rock sections. It is well known that there is in 
 biotite a maximum absorption of a plane polarised 
 light ray when the plane of vibration coincides 
 with the plane of cleavage. A section across the 
 cleavage then shows a maximum amount of 
 absorption. A halo seen on this section simply 
 produces this effect in a more intense degree. 
 This is well shown in Fig. 3 (ante) on a portion 
 of the halo-sphere. The descriptive name 
 " Pleochroic Halo " has originated from this 
 fact. We must conclude that the effect of the 
 ionisation due to the alpha ray has not been to 
 alter fundamentally the conditions which give 
 rise to the optical properties of the medium. 
 The increased absorption is probably associated 
 with some change in the chemical state of the iron 
 present. Haloes are, I believe, not found in 
 minerals from which this element is absent. One 
 thing is quite certain. The colouration is not due 
 to an accumulation of helium atoms, i.e., of spent 
 alpha rays. The evidence for this is conclusive. 
 If helium was responsible we should have haloes 
 produced in all sorts of colourless minerals. 
 Now we sometimes see zircons in felspars and in 
 quartz, etc., but in no such case is a halo pro- 
 duced. And halo-spheres formed within and 
 sufficiently close to the edge of a crystal of mica 
 are abruptly truncated by neighbouring areas of 
 felspar or quartz, although we know that the rays 
 must pass freely across the boundary. Again it 
 
PLEOCHROIC HALOES 151 
 
 is easy to show that even in the oldest haloes the 
 quantity of helium involved is so small that one 
 might say the halo-sphere was a tolerably good 
 vacuum as regards helium. There is, finally, no 
 reason to suppose that the imprisoned helium 
 would exhibit such a colouration, or, indeed, any 
 at all. 
 
 I have already referred to the great age of the 
 halo. Haloes are not found in the younger 
 igneous rocks. It is probable that a halo less 
 than a million years old has never been seen. 
 This, prim& fade, indicates an extremely slow 
 rate of formation. And our calculations quite 
 support the conclusions that the growth of a halo, 
 if this has been uniform, proceeds at a rate of 
 almost unimaginable slowness. 
 
 Let us calculate the number of alpha rays 
 which may have gone to form a halo in the 
 Devonian granite of Leinster. 
 
 It is common to find haloes developed perfectly 
 in this granite, and having a nucleus of zircon 
 less than 5 x icr 4 cms. in diameter. The volume 
 of zircon is 65* io' 12 c,cs. and the mass 3 X io' 10 
 grm. ; and if there was in this zircon icr 8 grm. 
 radium per gram (a quantity about five times the 
 greatest amount measured by Strutt), the mass 
 of radium involved is 3 x icf 18 grm. From this 
 and from the fact ascertained by Rutherford that 
 the number of alpha rays expelled by a gram of 
 radium in one second is 3*4 x io 10 , we find that 
 three rays are shot from the nucleus in a year. If 
 
iS2 HUXLEY MEMORIAL LECTURES 
 
 now, geological time since the Devonian 
 is 50 millions of years, then 150 millions 
 of rays built up the halo. If geological 
 time since the Devonian is 400 millions of years, 
 then 1 200 millions of alpha rays are concerned in 
 its genesis. The number of ions involved, of 
 course, greatly exceeds these numbers. A single 
 alpha ray fired from radium C will produce 2*37 x 
 io 5 ions in air. 
 
 But haloes may be found quite clearly defined 
 and fairly dark out to the range of the emanation 
 ray and derived from much less quantities of 
 radioactive materials. Thus a zircon nucleus 
 with a diameter of but 3*4 x icr 4 cms. formed a halo 
 strongly darkened within, and showing radium A 
 and radium C as clear smoky rings. Such a 
 nucleus, on the assumption made above as to its 
 radium content, expels one ray in a year. 
 But, again, haloes are observed with less black- 
 ened pupils and with faint ring due to radium C, 
 formed round nuclei of rather less than 2 x icr 4 
 cms. diameter. Such nuclei would expel one ray 
 in five years. And even lesser nuclei will 
 generate in these old rocks haloes with their 
 earlier characteristic features clearly developed. 
 In the case of the most minute nuclei, if my 
 assumption as to the uranium content is correct, 
 an alpha ray is expelled, probably, no oftener 
 than once in a century; and possibly at still 
 longer intervals. 
 
 The equilibrium amount of radium contained 
 
PLEOCHROIC HALOES 153 
 
 in some nuclei may amount to only a few atoms. 
 Even in the case of the larger nuclei and more 
 perfectly developed haloes the quantity of radium 
 involved is many millions of times less than the 
 least amount we can recognise by any other 
 means. But the delicacy of the observation is 
 not adequately set forth in this statement. We 
 can not only tell the nature of the radioactive 
 family with which we are dealing; but we can 
 recognise the presence of some of its constituent 
 members. I may say that it is not probable the 
 zircons are richer in radium than I have assumed. 
 My assumption involves about 3 per cent, of 
 uranium. I know of no analyses ascribing so great 
 an amount of uranium to zircon. The variety 
 cyrtolite has been found to contain half this 
 amount, about. But even if we doubled our 
 estimate of radium content, the remarkable nature 
 of our conclusions is hardly lessened. 
 
 It may appear strange that the ever-interesting 
 question of the Earth's age should find elucida- 
 tion from the study of haloes. Nevertheless the 
 subjects are closely connected. The circum- 
 stances are as follows. Geologists have esti- 
 mated the age of the Earth since denudation 
 began, by measurements of the integral effects of 
 denudation. These methods agree in showing 
 an age of about io 8 years. On the other hand, 
 measurements have been made of the accumula- 
 tion in minerals of radioactive debris the helium 
 and lead and results obtained which, although 
 
i 5 4 HUXLEY MEMORIAL LECTURES 
 
 they do not agree very well among themselves, 
 are concordant in assigning a very much greater 
 age to the rocks. If the radioactive estimate is 
 correct, then we are now living in a time when 
 the denudative forces of the Earth are about 
 eight or nine times as active as they have been on 
 the average over the past. Such a state of things 
 is absolutely unaccountable. And all the more 
 unaccountable because from all we know we 
 would expect a somewhat lesser rate of solvent 
 denudation as the world gets older and the land 
 gets more and more loaded with the washed-out 
 materials of the rocks. 
 
 Both the methods referred to of finding the 
 age assume the principle of uniformity. The 
 geologist contends for uniformity throughout the 
 past physical history of the Earth. . The physicist 
 claims the like for the change-rates of the radio- 
 active elements. Now the study of the rocks 
 enables us to infer something as to the past his- 
 tory of our Globe. Nothing is, on the other 
 hand, known respecting the origin of uranium or 
 thorium the parent radioactive bodies. And 
 while not questioning the law and regularity 
 which undoubtedly prevail in the periods of the 
 members of the radioactive families, it appears to 
 me that it is allowable to ask if the change rate of 
 uranium has been always what we now believe it 
 to be. This comes to much the same thing as 
 supposing that atoms possessing a faster change 
 rate once were associated with it which were 
 
PLEOCHROIC HALOES 155 
 
 capable of yielding both helium and lead to the 
 rocks. Such atoms might have been collateral in 
 origin with uranium from some antecedent 
 element. Like helium, lead may be a derivative 
 from more than one sequence of radioactive 
 changes. In the present state of our knowledge 
 the possibilities are many. The change rate is 
 known to be connected with the range of the alpha 
 ray expelled by the transforming element; and 
 the conformity of the halo with our existing know- 
 ledge of the ranges is reason for assuming that, 
 whatever the origin of the more active associate 
 of uranium, this passed through similar elemental 
 changes in the progress of its disintegration. 
 There may, however, have been differences in the 
 ranges which the halo would not reveal. It is 
 remarkable that uranium at the present time is 
 apparently responsible for two alpha rays of very 
 different ranges. If these proceed from different 
 elements, one should be faster in its change rate 
 than the other. Some guidance may yet be forth- 
 coming from the study of the more obscure 
 problems of radioactivity. 
 
 Now it is not improbable that the halo may 
 contribute directly to this discussion. We can 
 evidently attack the biotite with a known number 
 of alpha rays and determine how many are re- 
 quired to produce a certain intensity of darken- 
 ing, corresponding to that of a halo with a nucleus 
 of measureable dimensions. On certain assump- 
 tions, which are correct within defined limits, we 
 
156 HUXLEY MEMORIAL LECTURES 
 
 can calculate, as I have done above, the number 
 of rays concerned in forming the halo. In doing 
 so we assume some value for the age of the halo. 
 Let us take the maximum radioactive value. A 
 halo originating in Devonian times may attain a 
 certain central blackening from the effects of, 
 say, io 8 rays. But now suppose we find that we 
 cannot produce the same degree of blackening 
 with this number of rays applied in the laboratory. 
 What are we to conclude ? I think there is only 
 the one conclusion open to us : that some other 
 source of alpha rays, or a faster rate of supply, 
 existed in the past. And this conclusion would 
 explain the absence of haloes from the younger 
 rocks ; which, in view of the vast range of effects 
 possible in the development of haloes, is, other- 
 wise, not easy to account for. It is apparent that 
 the experiment on the biotite has a direct bearing 
 on the validity of the radioactive method of esti- 
 mating the age of the rocks. It is now being 
 carried out by Professor Rutherford under reli- 
 able conditions. 
 
 Finally, there is one very certain and valuable 
 fact to be learned from the halo. The halo has 
 established the extreme rarity of radioactivity as 
 an atomic phenomenon. One and all of the 
 speculations as to the slow breakdown of the 
 commoner elements may be dismissed. The 
 halo shows that the mica of the rocks is radio- 
 actively sensitive. The fundamental criterion of 
 radioactive change is the expulsion of the alpha 
 
PLEOCHROIC HALOES 157 
 
 ray. The molecular system of the mica and of 
 many other minerals is unstable in presence of 
 these rays, just as a photographic plate is unstable 
 in presence of light. Moreover, the mineral 
 integrates the radioactive effects in the same way 
 as a photographic salt integrates the effects of 
 light. In both cases the feeblest activities be- 
 come ultimately apparent to our inspection. We 
 have seen that one ray in each year since the 
 Devonian period will build the fully formed 
 halo : unlike any other appearance in the rocks. 
 And we have been able to allocate all the haloes 
 so far investigated to one or the other of the 
 known radioactive families. We are evidently 
 justified in the belief that had other elements 
 been radioactive we must either find characteris- 
 tic haloes produced by them, or else find a com- 
 plete darkening of the mica. The feeblest alpha 
 rays emitted by the relatively enormous quantities 
 of the prevailing elements, acting over the whole 
 duration of geological time and it must be re- 
 membered that the haloes we have been studying 
 are comparatively young must have registered 
 their effects on the sensitive minerals. And thus 
 we are safe in concluding that the common 
 elements, and, indeed, many which would be 
 called rare, are possessed of a degree of stability 
 which has preserved them unchanged since the 
 beginning of geological time. Each unaffected 
 flake of mica is, thus, unassailable proof of a fact 
 which but for the halo would, probably, have 
 been for ever beyond our cognisance. 
 
246 
 Range in cms of air 
 
 Fig. i. 
 
Fig. 2. 
 
Fig. 3- 
 
Fig. 4. 
 
p 
 
 Fig. 6. 
 
Fig. 7. 
 
Fig. 8. 
 
Fig. 9. 
 
159 
 
 INDEX 
 
 Action, the result of memory grasping facts successfully, 116 
 
 Alpha ray, conditions of its passage in mica, 148 
 
 Alpha ray, discovery of, fraught with momentous bearings 
 
 upon geological science, 137 
 
 Alpha ray, nature of the change produced by, 149 
 Alpha ray, velocity of the, 129 
 Atoms, opposition of, to rays, 132 
 Automatism, 121 
 
 Beagle, voyage of the, and Darwin's early researches, 45 
 
 Bible teaching, Huxley's position in relation to, 25 
 
 Biological inquiry, new school of, under Huxley's lead, 16 
 
 Biological laboratOTies, introduction of, 19 
 
 Biology, Huxley's work in, 14 
 
 Biology, the science of, split up into* several branches, 17 
 
 Huxley's teaching and view point, 18 
 
 Biotite, pleochroic haloes indicating action of alpha ray in, 138 
 Bragg's discovery of the " stopping power '' of atoms, 134 
 Brain (the) and consciousness, 106 
 
 its functions, 107 
 
 functions of, in lower organisms, 109 
 
 Brain/ (the human) possesses power to oppose automatism, 122 
 
 Character : Huxley's efforts foir teaching which should build 
 
 up character, 25 
 Chemical composition of a medium a basis for calculating 
 
 the power of pemetration of rays, 135 
 Church, Huxley's conflict with the, 33 ; his position, 33 
 
 its opposition to natural knowledge, 40 
 
 Comparative anatomy, Huxley's memoirs on, 13 
 Conduct of life, Huxley's view of, 28 
 Consciousness a hyphen between past and future, 105 
 Consciousness in the lowest organisms, 112 
 
160 INDEX 
 
 Consciousness, its relations with nature and life, 99 
 Consciousness : what is meant by the term, 103 
 Conventional notions on the facts of ancient history, 76 
 Creation, the triumph of life expressed in, 126 
 
 Darwin's early studies in evolution, 45 
 
 Darwin's Origin of Species, Huxley's championship of, 36 
 
 Democracy the ruling power, 66 
 
 Descartes, Huxley's essay on, 79 
 
 Divine guidance and command claimed among ancient 
 
 peoples, a substitute for reason, 58 
 Divine ideas as the basis of human progress, 56 
 
 Earth, age of the, elucidated from the study of haloes, 153 
 Education: Huxley's work on the London School Board, 21; 
 
 his theory of teaching, 22, et seq; school methods, 23 ; 
 
 his moral standpoint, 25 ; his views on secular education, 
 
 27 
 
 Education, scientific, importance of, 71 
 Environment, Rudimentary beings as well adapted to, as 
 
 man, 120 
 
 Environment, spiritual, 64 
 Evil, power of, stronger than the povrer of good (J. S. Mill's 
 
 view), 70 
 
 Evolution of species, 119 
 Explosive nature of the energy used for directing movement, 
 
 H5 
 
 Foodstuffs storing up energy for movement in conscious 
 
 animals, 115 
 
 French Revolution, faults in its efforts to remould society, 88 
 Future state, natural knowledge brings no proof of a, 34 
 
 Gases, range or distance travelled at ordinary pressure, 130 
 Geiger's proof of the existence of scattering of the haloes by 
 
 solids, 147 
 Good, power of, not so strong as the power of evil (J. S. 
 
 Mill's view), 70 
 Greek susceptibility to ideas, 56, 57 
 
 Halo development, 144 
 Halo, formation of a, 141 
 Haloes, " under-exposed," 143 
 
INDEX 161 
 
 Helium atom, the, 129 
 
 History, the study of, 73 
 
 Human progress due to creative and life-giving impulses, 56 
 
 Human race, unity of the history of, QI 
 
 Human science, how the study of, should be organised, 94 
 
 Human science, the twentieth century, the great age of, 83 
 
 Huvelin, M.P., on the importance of historical studies, 75 
 
 Huxley , lecture on, by Sir Michael Foster, 9 et seq 
 
 Huxley, a philosopher and a theologian, 53 
 
 Huxley and Natural Selection, by Prof. E. B. Poulton, 45, 
 et seq 
 
 Huxley not a Materialist, 5 
 
 Huxley, as a member of the London School Board, 21 
 
 Huxley, his connection with Birmingham, 4; his love of 
 knowledge, 10 ; his interest in machinery, n : his early 
 wish to be an engineer, 12; his labours in the field of 
 comparative anatomy, 13; his voyage on the Rattlesnake 
 and its results, 14; Huxley as a teacher, 16 
 
 Huxley, his conflict with the Church, 33 ; his championship of 
 Darwin, 36 
 
 Huxley lectures, complete list of, 5 
 
 Ideas, intellectual presentation of, 66 
 
 Impulse in low organisms to advance into a higher state, 120 
 
 Inquiry, spirit of, calling in question established principles, 
 
 68 
 
 lonisation effected by various rays, 131 
 lonisation, nature of, attending the passage of the rays, 136 
 
 Jews, the, owe their place in history to their belief in divine 
 
 government, 56, 57 
 Joy, a signal of the triumph of life, 125 
 
 Leibnitz's definition of matter, 104 
 
 Life and Consciousness, by H. Bergson, 99 et seq 
 
 Life, conduct of, Huxley's view of, 28 
 
 Life, entrance of, into the world, 113 
 
 Literary education imperfect unless accompanied by scientific 
 
 teaching, 71 
 
 Lodge (Sir Oliver), Life and Matter, 127 
 London School Board, Huxley's connection with, 21 
 
i62 INDEX 
 
 Machinery, Huxley's keen interest in, 1 1 
 
 Malthus " on Population," influence of, on Darwin's theory 
 
 of natural selection, 45 ; and on Wallace's studies in 
 
 evolution, 46 
 Man, evolution of, the unique instance of the power of 
 
 evolution to break the chain of automatism, 122 
 Man, nature of, to be regarded as a whole, 29 
 Man should be the subject-matter of teaching, 71, 73 
 
 the historic sciences as applied to the study of man, 73 
 
 psychological science as applied to, 77 
 
 sociological science as applied to, 79 
 
 Mason College, foundation stone of, laid by Huxley, 4 
 
 Materialism, Huxley not a supporter of, 6 
 
 Memory, a rapid series of successive vibrations, 117 
 
 Memory and consciousness, 103 
 
 Mica, the cleavage phenomenon in, 148 
 
 Mica, existence of uranium and thorium haloes in, 142 
 
 Mill, John Stuart, writings of, 68; his view on the religious 
 
 observance of Sunday, 69 
 Mind (the), is consciousness, 103 
 Moral nature, aspirations of our, not contradicted by positive 
 
 science, 127 
 Movement, how a conscious animal obtains power of, from 
 
 matter, 115 
 
 Natural knowledge, improvement of, important, 31 
 
 gives man directive agencies and power for the conduct 
 
 of life, 32 
 
 Natural selection (Huxley and), 45 et seq 
 
 Philosophy, meagre light thrown by older systems of, on the 
 
 problem of consciousness, 100 
 
 Plants, basic quality of all food derived from, 115 
 Pleochroic Haloes, by Prof. John Joly, 129 et seq 
 
 origin of the term, 150 
 
 great age of, 151 
 
 Priestley, Joseph, statue of, unveiled by Huxley, 4 
 Psychological science, importance of, as applied to the study 
 
 of Man, 78 
 Psychology of Religion, 78 
 
INDEX 163 
 
 Radioactivity, 136 
 
 Radioactivity, extreme rarity of, as an atomic phenomenon, 
 
 established by the halo, 156 
 Radium, largely present in Zircon, 138 
 Rationalism and Science in relation to Social Movements., 53 
 
 et seq 
 
 Rationalism and divine inspiration, 59 
 Rationalism, definition of, 55 
 Rattlesnake, Huxley's voyage on the, 14 
 Religion, Psychology of, 78 
 Religion, Unsectarian, Huxley's position as to religious 
 
 teaching, 25 
 Research studentships necessary to the study of human 
 
 science, 95 
 
 Revelation and reason, 58 
 
 Rights of man, doctrine of, " dead as Rousseau," 68 
 Rocks, the work of the alpha ray recorded visibly on, 137 
 Romans, the, their sense of civic law and order, 56, 57 
 
 Science and rationalism in relation to social movements, 53 
 
 et seq 
 
 Science, definition of, 55 
 
 Science, spirit of, different, from the spirit of rationalism, 70 
 Scientific education, importance of, for the well-being and 
 
 progress of society, 71 
 
 Scientific work reproductive and fertile, 14 
 Secular education, Huxley's views on, 27 
 Sensation, nature of, 117 
 Slavery abolition controversy, ethical versus rational impulse 
 
 of, 60 
 
 effect of competition between a slave-holding and a non- 
 slave-holding state, 62 
 Social movements, rationalism and science in relation to, 53 
 
 et seq 
 
 Socialism and its results, 84 
 Sociological science, importance of, as applied to the study of 
 
 man, 79 
 Specialism, extreme, importance of avoiding, in human 
 
 science, 93 
 Spinal cord (the), a storehouse of ready-made complex actions, 
 
 1 08 
 
164 INDEX 
 
 Spiritual environment, and the commonwealth of spirit, 64 
 Spontaneous motion in the vegetable world, in 
 Stomach (the), and the digestive processes, 105 
 Sunday, religious observance of (J. S. Mill's view), 69 
 Superficiality, importance of avoiding, in human science, 93 
 Survival of the fittest, principle of, exemplified, 63 
 
 Teaching, Huxley's theory of, 22 
 Thought, expression of, in words, 123 
 
 Thought, materialisation of, into literary or artistic form, 124 
 Town-planning, in reality a branch of human science, 80; 
 value of the study of ancient architecture in, 82 
 
 Universities should become great schools of human science, 89 
 Vegetable world, spontaneous motion in the, in 
 
 Wallace, A. R. : synchronism of his discovery of evolution 
 with that of Darwin, 46 
 
 Zircon, quantity of radium found in, 138 
 
 
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