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Descartes (1596-1650)
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Introduction

Main (philosophical) works:
Discourse (1637)
Meditations (1641)
Principia Philosophicae (1644)
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Methodology

Introspection and anti-elitism
My plan has never gone beyond trying to reform my own
thoughts and construct them upon a foundation which is all
my own. (Discourse on the Method; CSM I: 118)
Good sense is the best distributed thing in the world … the
power of judging well and of distinguishing the true from
false—which is what we properly call ‘good sense’ or
‘reason’—is naturally equal in all men, and consequently that
the diversity of our opinions does not arise because some of us
are more reasonable that others but solely because we direct our
thoughts along different paths and do not attend to the same
things. (Discourse on the Method; CSM I: 111)
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
Break away from the Scholastic tradition:
And if I am writing in French, my native language, rather than
Latin, the language of my teachers, it is because I expect that
those who use only their natural reason in all its purity will
be better judges of my opinion than those who give
credence only to the writings of the ancients. (Discourse on the
Method; CSM I: 151)
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Cartesian Feminism

Poullain de la Barre (1647-1723)

Published anonymously in 1673 On the Equality of the Two Sexes.
(Poullain de la Barre (2002). Three Cartesian Feminist Treatises. U. of
Chicago Press)

He brings Cartesian objectivity to gender issues in addressing
cultural inequalities between the sexes.

By systematically employing Cartesian methodology Poullain
rejected tradition as a means of dealing with the issues of
feminism.
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
Based on Descartes’ cogito argument that establishes the
superiority o the mind over the body, Poullain extended the
challenge of rational thinking to the polemic of sex and gender.

Since the mind has no sex, discrimination between the sexes
could not be accepted as the truth whether enshrined by
tradition or not.

The female gender carried as much intellectual potential as its
male counterpart because a lack of physical strength had no
correlation with a weaker mind.

Only customs and traditions have predetermined women
subordinate status.
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
Fallacious argument :
This is the way things have always been done, therefore they
should be done this way.

Had women been allowed to engage in public responsibilities,
they would never have been excluded from it in the first place.

To hold to custom and usage because they are sanctioned by
time (and male privilege) is pure prejudice.

Poullain arguments apply to class distinction as well:
How many peasants might have become renewed scholars if
they had been given a chance?
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Descartes Innovation/Main
Contribution

Mathematics is Central

“Scientific” Revolution:
Break away from Scholastics

Philosophical Knowledge:
(i) unity
(ii) purity and
(iii) certainty
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The Method of Doubt

Descartes’ Method. Anti-elitist: truth is not reserved
to highly trained minds.

Method of Doubt. An epistemological enterprise. The
malicious demon and the dream argument.
So, for the purpose of rejecting all my opinion, it will be enough
if I find in each of them [opinions] at least some reason for
doubt. And to do so I will not need to run through them all
individually, which would be an endless task. Once the
foundations of a building are undermined, anything built on
them collapses of its own accord; so I will go straight to the
basic principles on which my former beliefs rested. (First
Meditation; CSM II: 17)
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I thought it necessary to do the very opposite and reject as if absolutely false
everything in which I could imagine the least doubt, in order to see if I was
left believing anything that was entirely indubitable. Thus, because our senses
sometimes deceive us, I decided to suppose that nothing was such as they led us
to imagine. And since there are men who make mistakes in reasoning, committing
logical fallacies concerning the simplest questions in geometry, and because I
judged that I was as prone to error as anyone else, I rejected as unsound all the
arguments I had previously taken as demonstrative proofs. Lastly, considering that
the very thoughts we have while awake may also occur while we sleep
without any of them being at that time true, I resolved to pretend that all the
things that had ever entered my mind were no more true than the illusions of my
dreams. But immediately I noticed that while I was trying thus to think everything
false, it was necessary that I, who was thinking this, was something. And
observing that this truth ‘I am thinking, therefore I exist’ was so firm and
sure that all the most extravagant suppositions of the sceptics were
incapable of shaking it, I decided that I could accept it without scruple as the
first principle of the philosophy I was seeking. (Discourse on the Method; CSM I:
126-7)

Within the methodology of doubt, the malicious demon is
merely supposed/posited for the sake of the argument.
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The Cogito Argument

The First Principle. This brings a stop to the doubt.
I have convinced myself that there is absolutely nothing in the
world, no sky, no earth, no mind, no bodies. Does it follow tat I
too do not exist? No: if I convinced myself of something
then I certainly existed. But there is a deceiver of supreme
power and cunning who is deliberately and constantly deceiving
me. In that case I too undoubtedly exist if he is deceiving me;
and let him deceive me as much as he can, he will never bring it
about that I am nothing so long as I think that I am
something. So after considering everything very thoroughly, I
must finally conclude that this proposition, I am, I exist, is
necessarily true whenever it is put forward by me or
conceived in my mind. (Second Meditation; CSM II: 16-7)
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At least as I have discovered it—thought; this alone is
inseparable from me. I am, I exist—that is certain. But for
how long? For as long as I am thinking. For it could be that
were I totally to cease from thinking, I should totally cease to
exist. (Second Meditation; CSM II: 18)

The cogito argument does not rest on the standard
syllogistic reasoning:
(1) Whatever is thinking exists
(2) I am thinking
So: (3) I exist
When someone says ‘I am thinking, therefore I am, or I exist’,
he does not deduce existence from thought by means of
a syllogism, but recognizes it as something self-evident by a
simple intuition of the mind. This is clear from the fact that
if he were deducing it by means of a syllogism, he would have
to have had previous knowledge of the major premiss. (Second
Set of Replies; CSM II: 100)
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
Why not “I see, I exist” or “I walk, I exist”?
For example, I am not seeing light, hearing a noise, feeling heat.
But I am asleep, so all this is false. Yet I certainly seem to see, to
hear, and to be warmed. This cannot be false; what is called
‘having a sensory-perception’ is strictly just this, and in this
restricted sense of the term is simply thinking. (Second
Meditation; CSM II: 19)

“It seems that I see” = “I think”
“It seems that I see, so I exist” = “I think, so I am”
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Is the Cogito an Inference?
When someone says ‘I am breathing, therefore I exist’, if he wants
to prove he exists from the fact that there cannot be breathing
without existence, he proves nothing, because he would have to
prove first that it is true that he is breathing, which is
impossible unless he has also proved that he exists. But if he
wants to prove his existence from the feeling of the belief he has
that he is breathing, so that he judges that even if the opinion
were untrue he could not have it if he did not exist, then his
proof is sound. For in such a case the thought of breathing is
present to our mind before the thought of our existing, and we
cannot doubt that we have it while we have it. (Letter to Reneri for
Pollot, April or May 1638; CSMK III: 98)

Qualia (sensations):
are central, self-reflection, introspection
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External World

If external objects exist, their true nature is
perceived by the intellect, not by the senses
(which can deceive us). Hence introspection is
crucial.

Thus, the importance in Descartes of the system
of ideas.
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Grasping/Entertaining Ideas of
Substances

One does not grasp a substance per se: one grasps a
property of that substance.

When we come to the mind qua substance, though, the
property one grasps of that substance is its thinking
property.

An idea may not represent a thing in the real world, yet
when one entertains an idea one cannot not seem to
have an idea.
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
Reply to Gassendi:
[Y]ou [Gassendi] make an incidental criticism as follows:
although I have not admitted that I have anything apart from a
mind, I nevertheless speak of the wax which I see and touch,
and yet this is impossible without eyes and hands. But you
should have noticed that I had carefully pointed out that I
was not here dealing with sight and touch, which occur by
mean of bodily organs, but was concerned solely with the
though of seeing and touching, which, as we experience every
day in our dreams, does not require these organs. (Reply to
Gassendi; Fifth Set of Replies; CSM II: 249)

Scepticism: From “It seems that I perceive” we
cannot infer the existence of the external world.
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
“I think, I am” qua Scientific Starting Block

Ontological Commitment. Ontology deals with the
part of metaphysic concerning the question what kind
of things there are.

Quine’s slogan: “to be is to be the value of a variable”.
[E]ntities of a given sort are assumed by a theory if and only if
some of them be counted among the values of the variables, in
order that the statements affirmed in the theory be true. (Quine
1953)
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
Quining Descartes:
With the cogito argument one is ontologically
committed to the existence of oneself qua thinking
thing.
In order to be successful in committing ourselves to the
existence of other things our theory must ultimately
rely on the first principle (the cogito) and brings in only
other indubitable, necessary, truths.
Descartes will appeal to God and this appeal can be
seen to be scientifically driven.
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The Self

Myself qua Substance
[F]rom the mere fact that each of us understands himself to be a
thinking thing and is capable, in thoughts, of excluding from
himself every other substance, whether thinking or extended, it
is certain that each of us, regarded in this way, is really
distinct from every other thinking substance and from
every corporeal substance. (Principles of Philosophy 1. 60; CSM I:
213)

Main Question. How do we escape from the realm of
subjective-self awareness?

God enters the picture.
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