This chapter discusses Descartes thoughts on the seat of the soul or that part of the body which the soul is directly and intimately united. Descartes explains the simplicity principle: If the soul is simple, or indivisible, it can interact directly with only one object at once, thus indivisible. For example, if an animal's heart is taken and cut into pieces, the soul's indivisibility means that the soul cannot act directly upon the dissected parts of the heart. Descartes also consistently (...) identified the pineal gland as the seat of the soul— partly because it was mobile, durable, protected from outside influence, and accessible to the nerves. It also explains that the mind is not affected by all parts of the body, but only the brain and one small part of the brain only where a certain part of the brain is affected while other parts are doing other things. This chapter finally reveals that the simplicity principle of Descartes will have strong difficulties in the final analysis in relation to the truth of God. (shrink)

This chapter examines Peter Markie's book, “Descartes Gambit,” Edwin Curley's work titled “Descartes Against the Skeptics” and the exchange of criticisms between the two works. The “gambit” Markie refers to in his title is Descartes' attempt to deduce a metaphysical theory of the self from premises about his knowledge of himself. The epistemological premises are that “I am certain that I think”, that “I am certain that I exist”, and that “I am uncertain that I have a body.” The metaphysical (...) theory of the self derived from these premises is, roughly, that I am a thinking, nonextended substance capable of existing apart from its body. Markie maintains that Descartes himself held that these metaphysical conclusions could be deduced from these epistemological premises without establishing God's existence and veracity. The point of contention between the two works is on the definition and relationship of three species of Cartesian certainty— psychological, moral, and metaphysical. (shrink)