Abstract

How are we to understand Descartes' view on the power and scope of reason? According to a common view, Descartes traffics in what I call 'theocentric rationalism.' Theocentric rationalism holds that human reason resembles divine reason, according to which God created the world. A hallmark of this view is the notion that knowledge should be analyzed and evaluated according to the standards of cognition achievable by God. ;My dissertation argues that Descartes resisted treating human reason as resembling divine reason. This is supported by Descartes' theological voluntarism which denies that God is bound by the standards of human reason. Rather, Descartes conceived of reason as a natural power. He argued that reason is a power of mental substances, as much a part of the natural world as powers belonging to their counterpart, bodily substances. This conception of reason led Descartes to a view which I call "naturalistic rationalism." It holds that human knowledge is subject to the constraints and limitations imposed by our natural faculties human knowledge should be analyzed and evaluated according to the standards of cognition achievable by humans, given these limitations. According to my interpretation, Descartes did not seek to justify human reason by recourse to independent standards, such as divine reason. ;My case for this interpretation takes the form of a narrative tracing the development of Descartes' views on reason. Descartes' theory of reason emerged from his first systematic project, the method. Because Descartes held that method must employ the cognitive faculties properly, this early work, particularly the unpublished Regulae ad Directionem Ingenii , provides extensive discussions of reason, its proper function and its limits. I argue that Descartes' mature metaphysical work continued to uphold the central claims of his early theory of reason, in particular, the view that reason is a natural power, subject to natural constraints. ;This reading draws attention to the often neglected philosophical influence of Descartes' close friend, Marin Mersenne. Furthermore, my reading demonstrates the continuity of Descartes' early and later work. Most importantly, my reading allows us to better appreciate the significant differences between Descartes' rationalism and other rationalists