The concept of divine will constitutes one of the most fundamental issues in Christian theology and the history of Western philosophical thought. This notion not only plays a crucial role in explaining the relationship between God, reason, and morality, but also serves as a cornerstone for the emergence of new conceptions of human nature, freedom, and rationality in the modern age. Focusing on two key figures—William Ockham and René Descartes—this study undertakes a comparative analysis of the transformation of the meaning of divine will from the late Middle Ages to the dawn of modern philosophy. The central question is whether Descartes’ conception of divine will represents a radical rupture from the medieval scholastic tradition or, rather, a logical continuation of Ockham’s voluntarism reformulated in an epistemological and philosophical framework. Addressing this question helps to clarify the relationship between scholastic theology and modern philosophy, while revealing the historical roots and wide-ranging implications of voluntarism in Western thought.
The research method is analytical and comparative. In the first stage, the fundamental concepts of Ockham’s and Descartes’ thought concerning God, reason, and will are identified and examined conceptually. These views are then compared across four analytical axes: (1) the relation between divine reason and will, (2) the status of eternal truths, (3) the origin of morality, and (4) the epistemological consequences of their respective positions. Finally, based on these analyses, the relationship between the two systems is interpreted as one of inner continuity rather than absolute rupture.
The first part of the study examines Ockham’s philosophy as the culmination of late scholastic theology. Critiquing the legacy of Greek philosophy and emphasizing the doctrine of God’s absolute power (potentia Dei absoluta), Ockham presents a conception of God whose will precedes and surpasses any rational, logical, or moral necessity. Rejecting the real existence of universals (nominalism) and the necessitarianism of Aristotelian thought, and distinguishing between God’s absolute and ordained power, Ockham portrays God as possessing an utterly free and unlimited will, constrained by nothing—not even by logical laws, eternal truths, or moral necessities. Consequently, moral laws themselves are created by divine will and could have been entirely different. This position leads to the Divine Command Theory in ethics, according to which good and evil depend solely on God’s command and prohibition. The epistemological outcome of such a view is the severe limitation of human reason in knowing God and the elevation of faith as the only path to divine truth.
The second part analyzes Descartes’ philosophy as the turning point of modern thought. Within a new framework grounded in methodic doubt and the quest for certainty, Descartes redefines the role of God not only in metaphysical foundations but also as the guarantor of human knowledge. Like Ockham, Descartes conceives divine will as absolute and free; however, unlike Ockham, he considers this will to be the very ground of stability for eternal truths and the foundation of rationality. In his writings, necessary and self-evident truths—such as mathematical and logical laws—are created by divine will, yet it is this same absolute will that guarantees their permanence and validity. Thus, God is both the creator of existence and the creator of the essences and laws of things; and the world, owing to the constancy of divine will, enjoys a stable and orderly structure. Within this framework, Descartes regards human reason as valid insofar as it relies on clarity and distinctness; yet its ultimate reliability depends upon God’s benevolence and veracity. In ethics as well, while Descartes attributes the ultimate foundation of good and evil to divine will, he connects it with the rational criterion of clarity and distinct perception. Hence, whereas in Ockham’s system divine will marginalizes reason, in Descartes’ philosophy the same absolute will becomes the foundation of the validity of reason and modern science.
The findings of the study demonstrate that Descartes, contrary to interpretations that emphasize a total break between the modern and medieval eras, stands in essential continuity with Ockham’s voluntarist tradition. He transfers the principle of the precedence of will over reason from its theological context into the epistemological and mathematical domain, thereby reinterpreting scholastic voluntarism within a new, modern framework. In other words, Cartesian philosophy represents the inner continuity of the medieval theology of divine will, now serving as the metaphysical foundation of modern science and rationality.
The study concludes that understanding the relation between divine will and reason in Ockham and Descartes not only clarifies the conceptual distance between medieval and modern thought but also reveals how a theological doctrine could become the historical matrix for the emergence of modern rationality. Ockham’s theology of absolute divine will, with its emphasis on God’s unrestricted omnipotence, paved the way for the rise of the autonomous human subject. Descartes, by rearticulating the same principle in philosophical terms, transformed divine will into the guarantor of certainty and the metaphysical ground of scientific knowledge. From this perspective, modernity should not be seen as a complete rupture from the Middle Ages but rather as an inner continuation of late scholastic theology, reconstituted in the form of modern rationality.