The question of Christ's wills arises naturally from Jesus' prayer in the garden of Gethsemane (Matthew 26:39). The question gained urgency during the seventhcentury monothelite controversy and was settled by the determination of the Third Council of Constantinople (680-681) that Christ had two natural, non-contrary wills, divine and human. Thirteenth-century debates, unlike those of the seventh-century, did not involve disagreement about Christ's possession of a human will. The dominant concern of thirteenth-century theologians was to affirm the fullness of Christ's humanity while denying contrariety of wills in Christ. The thirteenth century witnessed developments in the affirmation of Christ's full humanity and in strategies for denying contrariety of wills in Christ. The foundation for thirteenth-century discussions was Peter Lombard's Sentences. The Lombard distinguished Christ's will of reason and will of sensuality, arguing that Christ willed the Passion through reason but shunned it through sensuality. This implies no struggle, because Christ's sensuality did not extend beyond its natural limits. Rather, this testifies to the truth of Christ's humanity. William of Auxerre's Summa aurea developed a new strategy for noncontrariety, arguing that contrary wills must be in the same genus or part of the soul. The Summa fratris Alexandri added a division of Christ's will of reason, based upon John Damascene's distinction between thelesis and boulesis. Albert the Great and Bonaventure rejected William's strategy for non-contrariety and focused instead on the conformity of Christ's wills. Thomas Aquinas' mature presentation of Christ's two wills in the Summa theologiae benefited from knowledge of patristic and conciliar sources. Thomas stressed Christ's possession of a perfect human will and perfect free choice (liberum arbitrium). Thomas places remarkable stress on the work of Christ's human nature as instrument of the divinity causing salvation through efficient instrumental causality. Christ's free human will to suffer in the Passion causes salvation. God's use of a human instrument to cause salvation fittingly reflects the dignity of human nature in Thomas' theology.