PRINCIPLES OF
PHILOSOPHY
A Thinking Thing
Not only does the cogito prove Descartes'
existence, but, as Descartes next points out in principle I.8, it even
proves what he is. He is a thing that thinks. In order to
better understand what this means, Descartes tries to give a definition of
"thought" in principle I.9. By "thought" he tells us, he
means to refer to anything marked by awareness or consciousness. This does not
just include reasoning or other such intellectual activities but also
imagining, sensing, willing, believing, doubting, hoping, dreading, and all
other mental operations.
Having proved that he is a thinking being,
Descartes then goes on to prove that we know the existence of the mind better
than we know the existence of body. The argument, stated in principle I.11,
goes as follows: (1) Every attribute or quality must belong to some substance
(since this is in the very nature of an attribute or quality); (2) the more
attributes we discover of a substance the better we know it exists; (3)
whenever we come to know an attribute of anything, we also come to know an
attribute of our mind—the attribute responsible for our coming to know whatever
attribute it is we came to know. In addition, we come to know this mental
attribute with much more certainty than we come to know whatever other
attribute is in question. For instance, we might think we come to know what a
flower is by seeing it. However, we might be wrong to judge that the flower is
red. What we cannot be wrong about is that we made this judgment and that we
had this sensation. And thus we are reinforced in the knowledge that our mind
exists.
The conclusion that we know the existence of
our minds with more certainty than we know the existence of our own bodies is
counterintuitive, and Descartes next tries to account for why it seems so
strange to us. The reason that we tend to think we know our bodies as well, or
better, than we know our minds, he explains, is that we fail to distinguish
between our minds and our bodies. So though we realize that our own existence
is more certain than the existence of anything else, we mistakenly conclude
from this that it is the existence of our bodies, rather than our minds, which
is so certain.
After proving that he is a thinking thing, but
before proving that the mind is better known than the body, Descartes takes a
detour in principle I.10 to forestall an objection that he knows will be hurled
at him by Scholastic philosophers: his failure to provide definitions for
certain of his key terms, such as "existence," and
"awareness." He warns that he will continue to do this throughout the
text and explains that this is not an oversight or a symptom of sloppy
thinking. Rather, he believes that the meaning of these terms is so self-
evident that the attempt to provide a definition (as the Scholastics would
certainly do) would only needlessly confuse matters. This is the first of many
explicit jibes that Descartes will make against the Scholastic method of
philosophy.
Analysis
In I.8 Descartes concludes that he is a
thinking thing. But is that all he concludes? It looks suspiciously as if he is
also concluding that he is just a thinking thing. That is to
say, it looks as if he is concluding that the "I" he discovered can
be identified with the mind to the exclusion of body. Is this
really the case, though? Is Descartes concluding here not only, "I know
only that I am mind" but also "I know that I am only mind and not
body?"
Questions about this aspect of Descartes'
philosophy have been hotly debated ever since the initial publication of
Descartes' Meditations (a book which gives rise to the same
question). Imagine that Descartes is, in fact, arguing for the claim that he is
mind and not body. What would his argument be? His argument would have to be
the following: (1) I know that I am a thinking thing, (2) I do not know that I
am a bodily thing, (3) therefore, I am not a bodily thing. He would be
concluding a metaphysical claim from an epistemological claim, a claim about
what is from a claim about what he knows. A
fallacy of this sort is often referred to as an "ignorance fallacy"
because it assumes that one's own ignorance is proof of something in the world.
Descartes, however, seems to escape the noose
as far as this fallacy goes. He concludes principle I.8 with the following
words: "So our knowledge of our thought is prior to, and more certain
than, our knowledge of any corporeal thing; for we have already perceived it,
although we are still in doubt about many other things." This statement is
a clear affirmation that what he takes himself to have proved here is that, as
far as he knows, he is only a thinking thing. He does not think that he has
proved that he definitely is only a thinking thing. (Descartes
will introduce the proof for this latter claim later in Part I of the Principles;
that proof will rely on many of the conclusions that we will cover in the
intervening sections).
REFERENCE
Descartes, Rene. Principles
of Philosophy. Trans. Valentine Rodger Miller and Reese P. Miller.
Boston: Kluwer Academic Publishers, 1991.
Descartes, Rene. The
Philosophical Writings of Descartes. Trans. John Cottingham, Robert
Stoothoff, Dugold Murdoch. New York: Cambridge University Press, 1985.
Cottingham, John, ed. The
Cambridge Companion to Descartes. New York: Cambridge University
Press, 1992.
Des Chene, Dennis. Spitis
and Clocks: Machine and Organism in Descartes New York: Cornell
University Press, 2001.
Social Plugin