Download Descartes vision of Philosophy Methodic Doubt and the Cogito

Descartes
Perspectives in Philosophy
Rene Descartes
• Philosophy is the search for certainty…the
search to know, for yourself, what is really
true and really false…to know which
beliefs are reliable.
• However, in order to get certitude, we
must start with certitude…it isn’t
something we could mature into
(traditional belief of philosophy—for
example, Socrates’ wisdom)
Philosophy and Good Sense
Philosophy and Good Sense
• Everyone has good sense.
• It’s the most equally distributed thing in the
world.
• We are all our own philosophical experts
• Just like Luther thought that each of us
can interpret Scripture for ourselves…
• So there is no cave…the normal condition
of man is not one of ignorance about
fundamental philosophical truths….
• And we don’t need anyone to lead us
out…
Rejection of tradition…
• “I thought that the
sciences contained in
books … are farther
removed from truth than
the simple inferences
which a man of good
sense using his natural
and unprejudiced
judgment draws
respecting the matters of
his experience.”
Philosophy is not…
• Care of the soul, a
search to know
thyself, for human
happiness, for the
good life—for how we
best ought to live our
lives.
Do you consider yourself the best judge about
philosophical matters? As good as anyone else?
If not, why not?
Philosophical knowledge
View of Philosophy
• This is a rejection of the Greek (explicitly
Aristotle’s) insight that by ourselves we cannot
adequately find the truth, but collectively humans
have amassed a considerable amount of truth.
• Philosophy should not be a refinement and
elaboration of the common-sense knowledge
and understanding of the world and ourselves.
• Rejection of the Scholastic method exemplified
in St. Thomas’ Summae
• Socrates’ time spent in the agora was a waste of
time!
• Philosophy should solve problems and
move on to new ones….
• Like geometry…
• Philosophy isn’t a practice or way of life
where we need both intellectual and moral
training to see and understand the
answers that good wise persons have
come to see…
• …after all, we all have equal good sense.
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Morality
• As far as morality goes, Descartes can’t
think it is necessary for philosophical
success…
• After all, he says it was enough for him to
follow a provisional morality which said…
Discovering Truth
• The key to discovering the truth is having
the correct method.
• Socratic dialectic does not count as a
method!
• The method must be used on a reliable
foundation…
Looking for a good foundation
1. Philosophical beliefs
• Every philosophical
doctrine is disputed
by other philosophers
• So doubt is possible
about philosophical
beliefs
• We cannot use them
for our foundation…
Descartes’ Provisional Morality
• Obey the laws and
customs of my country,
and adhere firmly to the
Christian faith, regulating
his conduct by the most
moderate opinions
• Be as firm and resolute in
action as possible
• Conquer yourself rather
than fortune, knowing that
except for our thoughts,
there is is nothing
absolutely in our power.
The New Philosophy
• True philosophy needs to start again, to
build from scratch.
• It needs to be built by a single
person…Descartes creates the
“autonomous individual” who apparently
needs no community—neither for his sake
nor the community’s.
• The paradigm for philosophy is
mathematics.
Descartes’ Method of Doubt
• So he sets out "to rid [him]self of all the
opinions I had adopted, and of
commencing anew the work of building
from the foundation" (Meditation I).
Looking for a good foundation
2. Scientific beleifs
• These are not set on
the firmest
foundations (at his
time)
• So doubt is possible
about scientific beliefs
• We cannot use them
for our foundation…
Descartes’ Method of Doubt
• The method of doubt: Reject as false any idea
that could possibly be wrong
• “Nor for this purpose will it be necessary even to
deal with each belief individually, which would
be truly an endless labour; but, as the removal
from below of the foundation necessarily
involves the downfall of the whole edifice, I will
at once approach the criticism of the principles
on which all my former beliefs rested.”
Looking for a good foundation
3. Common sense beliefs:
3a. Perceptual beliefs:
• About the past: memories are often faulty. So it is
possible to be wrong about remembered beliefs.
• About the future: induction is only probable and
could well be mistaken. So it is possible to be
wrong about beliefs about the future.
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Looking for a good foundation
• Common sense beliefs:
– Perceptual beliefs:
• About the present: could all be a vivid dream, and
there is no way of telling the difference.
• Our present experience could be a trick caused by
an “evil genius”—a sort of evil god, so powerful
that he has the ability to deceive us into believing
all sorts of things that are not true.
Looking for a good foundation
Matrix as evil demon…
• Just like Neo was
fooled into
believing he was
really living an
entire life....
• When he was
just connected
to the matrix.
Looking for a foundation
• So it looks like we
have doubted just
about everything…
• Non-perceptual but seemingly indisputable
truths:
– could be a trick by the evil genius too. Your
feeling that you cannot doubt these truths
could be induced in you by this demon.
Possible even if not plausible?
Looking for a good foundation
• Is it possible to doubt that I am doubting?
• One statement/belief can never be
doubted: I think therefore I am.
• So I cannot be wrong that I exist. This will
become the basis of certainty for
everything else.
Descartes rebuilds everything
From there his argument goes basically like this:
1. Cogito ergo Sum: I exist and am a thinking being. (Rational
intuition—a deliverance of “good sense.”)
Corollary 1: I have ideas
Corollary 2: I am distinct from my body (contrast with St. Thomas)
2. Whatever I perceive clearly and distinctly is true (Basic principle)
[Implication of “good sense”—also needs a defense! See pg 25]
Descartes rebuilds everything
2. Whatever I perceive clearly and distinctly is true
(Basic principle) [Implication of “good sense”—
also needs a defense! See pg 25]
3. I perceive clearly and distinctly that the
existence of God is the only adequate cause of
my idea of God as the perfect being.
Descartes rebuilds everything
4.God is perfect—all powerful, all good.
5.Therefore, God would not let me believe
something so strongly if it was so wrong.
4. Therefore God exists.
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Descartes rebuilds everything
6. Therefore, the principle “whatever I perceive clearly and
distinctly is true” is a valid principle. [oh-oh — The
Cartesian circle? On Descartes, pgs 51-53.]
7. Therefore our strong natural tendency to believe in the
existence of a world of material objects and that our
ideas are caused by it, is reliable—at least in general.
Otherwise we would be massively deceived by God.
Therefore material objects (including my own body)—
exist. They do not necessarily exist as we perceive
them, but they nonetheless exist.
Philosophy after Descartes
Descartes rebuilds everything
8. Further development of science
(theorizing supported by observation) is
now secure and believable as truths
about a really existing world. Science’s
methodology and object now have a
“metaphysical” guarantee. Science has
also been reconciled with religious belief.
[Cf On Descartes, pg 51.]
Philosophy after Descartes
• Philosophy becomes a more technical and
highly abstract study, concerned as it is
with the difficult questions of justifying our
processes of knowing rather than looking
for ultimate causes of all reality, or the
ultimate purposes of human life.
• Philosophy has a twofold role:
Philosophy after Descartes
HOW ABOUT NOTHING?
• Kant showed that you cannot
prove God’s existence—so
Descartes proof fails.
• If philosophy does not justify
science—which it in fact did
not ever do (scientists care
little about what philosophers
say) … then WHAT DOES
philosophy do in the modern
world?
– (1) justifying science, its assumptions, and
methods; and
– (2) studying entities not susceptible of
scientific study, namely the human mind and
God.
Isn’t that what we all already think?
We know what physicists do for us, and
biologists, and psychologists and priests
and lawyers, but no one really can say
what philosophers do—what they add to
our lives.
Summary of the rebuild
1. I am certain that I
exist
2. I am certain that
God exists and is a
perfect being.
3. God supports my
belief in an world
outside myself that I
can study and learn
about in science.
Philosophy after Descartes
• But once
philosophers abandon
the possibility of truly
knowing themselves
or God—Kant will
argue that we can
know only what we
experience, not things
like God or the soul—
philosophy is left with
justifying science.
HOW ABOUT NOTHING!
Probably as good as an answer as
anything….!
After all, what do you go to a
philosopher for?
Advice about how best to live your life?
Resolving your doubts about whether
science really can tell us the truth about
reality? Or resolving apparent points of
conflict between two different sciences?
To learn about the nature and existence
of your soul? Of God?
I don’t need a philosopher to tell me if
a microscope really works….
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Philosophy
• The little orphan
science that has no
purpose in the
modern world…
Descartes on Philosophy
• Descartes moved to
Holland possibly to
avoid any trouble with
the Church, such as
happened to
Galileo…
Descartes on Philosophy
• What becomes of uppermost value in an
enterprise such as this is freedom,
freedom which
is an individual value, established against
the needs of the community.
Descartes on Philosophy
• How important did Socrates view his
freedom of inquiry, when it lead to his
arrest and sentencing to death? He
accepted a sentence of death…
Descartes on Philosophy
Two big questions
• Does Descartes end up advocating for a
small, powerful elite class of intellectuals
who will move society forward according to
the dictates of their own values, rather
than those of society?
• About method: what is the best/appropriate way to acquire
knowledge and learn the truth? Is it by group efforts, based on
shared beliefs and common-knowledge, and relying on agreement
and universal acceptance? [Socratic Dialectic] Or is it by individual
efforts that shun the views of others and boldly assert ones own
beliefs as the truth? [Cartesian Cogito] Most of us are very wary of
asserting truths or views that are opposed to the views of others—is
that a sign of strength or weakness on our part?
• About philosophy: what is the role of philosophy in society? Is it to
articulate and defend views believed by all, or is it a personal
enterprise design only for our individual satisfaction? Is the
philosophy proposed by Descartes of much use to the Church?
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