descartes

1. Philosophy 224
Human Nature and Modern Philosophy
Descartes

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. 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).
• 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).

4. 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 and
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.

5. 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.

6. 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, requires
acknowledgment of an underlying rationality. This requirement
is in turn demonstrated by the inability of an android to fool
anyone.