This dissertation is a study of Nicholas of Methone's Refutation (Ἀνάπυξις) of the neoplatonist Proclus' Elements of Theology. Despite being one of three full-length medieval commentaries on this work, Nicholas' Refutation has hitherto received relatively little attention. This dissertation aims to bring his work to a wider audience by providing an English translation of the work and a systematic study of its major themes. Chapter 1 briefly outlines the significance of the issues dealt with in Nicholas' work. Chapter 2 then sets the stage for Nicholas' Refutation by tracing the Christian reception of Proclus from Dionysius the Areopagite until Nicholas' time. Chapter 3 reviews the history of scholarship on Nicholas and the Refutation in particular, giving extended attention to the claim that his Refutation is plagiarized from an earlier work by Procopius of Gaza. Chapter 4, which is the heart of the dissertation, is an extended consideration of the major themes of Nicholas' work, and of how they relate to each other. I show that Nicholas' fundamental concern is to distinguish the Christian doctrines of Creation and Trinity from the Emanationist and Unitarian metaphysics of Proclus' Elements, and that apophatic theology plays a prominent role in Nicholas' defense of Christian teaching. In this chapter I also explore the tensions and ironies involved in Nicholas' attempt to read Dionysius against Proclus. In Chapter 5 I briefly survey aspects of Nicholas' work that await further attention, and I trace the reception of the Refutation in the Greek and Latin contexts. Appendix A, a complete English translation of Nicholas' Refutation, is this dissertation's most substantial contribution to scholarship, and is the foundation for my study of the Nicholas' thought in Chapter 4. Appendix B takes note of two manuscript "discoveries," and the table in Appendix C allows for an easy comparison between Nicholas' Chapter 122 and Proclus' Proposition 122 which it paraphrases.