1. HUMAN NATURE AND MODERN PHILOSOPHY DESCARTES PHILOSOPHY 224

2. RENE DESCARTES Descartes was born in 1591 in La Haye, France. He died in 1650 in Sweden. Educated by the Jesuits, he was dissatisfied with the products of what was at the time the best education possible. The problem as he saw it was the sterility and conflict of scholastic (church) philosophy, which was incapable of fending off skepticism. He set himself the task of providing an indubitable foundation for human knowledge. The foundation he found: Cogito, ergo sum.

3. MODERN PHILOSOPHY Descartes is the first philosopher of what is called Modern Philosophy. Though in actuality it is the philosophy of the 17th and 18th centuries, the era is called “Modern” because it marks the end of philosophy dominated by the church and by its concerns, and by the introduction of a number of themes still operative today. These themes include: the struggle against skepticism, the dominance of science and mechanism over spiritualism, and a focus on and confidence in subjectivity.

4. DISCOURSE ON METHOD Descartes begins by recounting the course of his Meditations, the purpose of which is to identify an indubitable foundation for knowledge (a realm of absolute truth). The course of the meditations takes us through hyperbolic doubt. In the process of doubting everything that is doubtable, Descartes locates the foundation that he is seeking (the Cogito: “I think, therefore I am”). When he applies the results of the doubting to the question of his own nature, what becomes apparent is that, while he could doubt his material being, the very fact of doubting indicates that he is necessarily a thinking being (86).

5. A PHILOSOPHICAL DUALISM This reflection on our nature, and its termination in the thinking subject, leads Descartes to articulate a dualistic conception of human nature. This conception is importantly different from the one common to many religious accounts. Descartes offers what is called mind-body (or psycho- physical) dualism. The schema that he offers distinguishes two completely distinct sort of substances/beings: Res Extensa aand Res Cogitans. The question for Descartes (and other mind-body dualists) concerns how two radically distinct natures could nonetheless be joined and united in a way consistent with our self-experience.

6. WHAT ABOUT OUR BODIES? The key feature of Descartes’s account of the body is that it is a machine. That means that every function of the body can be explained by mechanical interaction. The thoroughgoing mechanistic nature of Descartes’s account of the body is easily seen in his treatment of sensation. The sense organs contain “tiny fibers” which are stimulated by the objects of sense. The action of these fibers in turn pull on parts of the brain, which open the brain to the influence of the objects of sense, ultimately producing in the mind the sensed object.

7. UNITY? Since our self-experience is of a fundamental unity between our mind and our body, Descartes' account must attempt to link the mechanical properties of the body to the rational faculties of the mind or soul. In other places, he speculates that a rarefaction, by contraction, of the blood, eventually transforms a purely material stuff into “a certain very fine wind” the “animal spirits” (Treatise on Human Nature) which, in the pineal gland (itself a mixture of the two substances) enables the transition between mind stuff and body stuff. In the Discourse, we get a different account which focuses on the fact of the unity as its revealed in language, which requires acknowledgment of an underlying rationality. This requirement is in turn demonstrated by the inability of an android (a mechanical human) to fool anyone.

8. A MODERN PHILOSOPHER Though there is much to be critical of in Descartes account of mind/body dualism, it is clearly an account which abandons much of the religious (particularly Christian) conception of the human. “In order to explain these functions [of the body], then, it is not necessary to conceive of this machine as having any vegetative or sensitive soul…apart from its blood and its spirits which are agitated by the heat of the fire burning in its heart—a fire which has the same nature as all the fires that occur in inanimate bodies” (Treatise on Human Nature).