PHILOSOPHY 224
HUMAN NATURE AND MODERN PHILOSOPHY
DESCARTES
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.
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.
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).
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 psychophysical) 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.
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.
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.
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).