I made the generalization last time that Bacon, Descartes, Pascal
did an excellent
job helping provide order and assurance for the people of the 17th
century. Certainly Bacon's method of pursuing truth,
the inductive (or scientific) method is a good one--in areas for which
it is applicable. Bacon's method helped lead to the scientific
and put science on a much more stable footing than it had been
But Bacon's method doesn't work for everything--in fact for many of the
things we care
most about, it is no good at all. It is not surprising, then,
that other 17th century
thinkers looked for other means of obtaining certainty. One such,
Descartes (1596-1650) was a French mathematician and philosopher (1596-1650) and one of most brilliant men who ever lived. He was an outstanding mathematicians--perhaps the best in the world at the time. He invented analytic geometry, and we still talk of "Cartesian" coordinates when we do problems in analytic geometry today. Descartes prepared the way for Newton's discovery of calculus later in the 17th century. Descartes was also one of leading figures in science, as I'll explain later. But in some ways, Descartes' most important contribution was in field of philosphy. He wrote two particularly important philosophical essay, the Discourse on Method and Meditations on First Philosophy. In these books Descartes makes clear what he considers to be the best way of arriving at certainty.
Not from authority. Descartes had gone to a very good school
and he enjoyed his studies. But he was dissatisfied with what he
in school, having special problems with the fact that there were so
many conflicting "authorities" in many, many fields.
Not from experience. Much travel/many adventures doesn't make you more certain of the truth. The more you see, at least in some areas, the less sure you are of what's really true.
So where do you find certainty? By employing the methods of
mathematics: essentially, pure reason--what we call the deductive
BASIC STEPS OF DESCARTES' METHOD
Descartes lists the basic steps of his method:
1. Accept nothing that can be doubted (start with only a few
basic axioms that cannot possibly be doubted)
2. Break a problem into parts
3. Proceed in an orderly way from simple to complex
4. Go back over proof to make sure nothing is left out (make your proof rigorous)
ADVANTAGES AND DISADVANTAGES
There are some great advantages to this method:
1. There should be a great deal of certainty about one's
2. Anyone should be able to follow proof and get the same answer
Unfortunately, there are some disadvantages as well:
1. A Small error can lead to major problems. Consider
the following "proof":
x=y, w=z, a=1, b=2 (Given)
Where is the mistake?
Signing up for this class in the first place, perhaps! But notice the problem. There is hidden away in the above proof a "divide by zero error," and error that is very hard to catch. If one is attempting to follow Descartes method, one has to be very, very careful not to stumble over the equivelent of a "divide by zero" error. One has to look at every step of the proof carefully: skimming won't work!
2. Following Descartes' method may mean taking an enormous amount of time to prove anything worthwhile
In your high school geometry classes you almost certainly
found yourself taking a great deal of time to "prove" things that
seemed to you obvious at the outset. To prove anything at all
complicated wasn't quick at all. Descartes knows that this is a
potential problem, and so he adopts some provisional rules. How
do we conduct ourselves while we are searchng for certainty but haven't
necessarily found it yet? Here are the rules:
1. Follow the customs of your country. Just because you
are uncertain the laws and customs of your country are right, that's no
excuse for violating them. The wise man gives law and custom the
benefit of the doubt.
2. Be resolute. There are many practical questions that
have to be decided on best evidence, not certainty. When would
you choose a major if you first had to be absolutely sure that that was
the best major for you? When would you marry if you first had to
be absolutely sure that this was the best husband or wife for
you? There's no point in being an irresolute Hamlet type.
3. Resolve to change yourself rather than fortune. In
philosophical matters, what the wise man is looking for is ways to
change himself, not the world.
4. Choose best occupation. Descartes realizes that his
method is only useful to those who have the leisure for plenty of
thought about important issues: professional philosophers,
perhaps. If one plans to follow the method he advocates, find a
job that gives one the time to do so.
Having established these provisional rules, Descartes now suggests
the basic path one might take in pursuit of ultimate certainty.
One might think that Descartes, a great mathematician and scientist,
would begin by investigating the physical world. But, for reasons
that should become apparent, he thought it necessary to start with the
investiation of certain metaphysical questions, questions with issues
beyond (or more fundamental than) the physical world.
APPLICATION OF DESCARTES' METHOD TO METAPHYSICS
1. The first step of the method is to doubt all that can be doubted? And what's that? Everything! The things I think I see in the physical world might not be real at all. I might be crazy! (No might about it, say some of you, perhaps). In any case, Descartes says we should start with a completely blank slate: take nothing for granted at all.2. Now can we find a good starting point, any one thing can't be doubted? Yes, says Descartes. Here's one thing I know: I am thinking. But in order to think, I must exist. Therefore, since I know that I am thinking, I know I exist. The famous phrase from Descartes: Cogito Ergo Sum: I think therefore I am. You will see variations on this line all over the place, e.g., jokes. Descartes walks into a bar. The bartendedr asks if he wants a drink. Descartes says, "I think not." He disappears. And then there is this slogan one NSU woman wore on her sweatshirt: I think, therefore I am....single. My favorite version of this is from a family conversation some years back. When my youngest daughter, Laurie, was four, her older brother, RJ would constantly tease her. For a while, one of his favorite "tease" lines was, "You don't exist." Finally, Laurie's older sister Becky gave her this advice: the next time RJ tells you you don't exist, quote Descartes: I think, therefore I am.
5. Now consider the relationship betwen two important ideas,
my idea of God and my idea of myself. My idea of God is that God is a
perfect, all-powerful creator who has existed from all eternity.
My idea of myself is of an imperfect, finite creature who hasn't been
around all that long. Now is one of these
ideas contingent on the other? Could there be a God without an
Art Marmorstein? Of course there could. God's existence is
obviously not contingent on the existence of a finite being like
myself. But could there be an Art Marmorstein without God? No--it
doesn't seem possible for a being like myself to come into existence
without the creative act of a trancendent being. My existence,
then, is contingent on God's existence.
But what do we know about me
(we know your boring and that you tell stupid jokes). Well, ok.
But what I know philosophicall is that I exist (cogito ergo sum).
And if I exist, and my existence is contingent on God's existence, then
God must also exist! We have proved the existence of God!
THE APPLICATION OF DESCARTES'
METHOD TO THE PHYSICAL WORLD
Descartes' jump from his own existence to God's doesn't seem completely justified. Is it really so that I couldn't exist unless there was a God, and that my existence demonstrates that God must exist?
This is, of course, is one of the central question in the
Descartes does his best to show that the existence of God really cannot
be doubted. He does this in a number of ways, modifiying some of
the traditional arguments for the existence of God and, in each case,
improving and expanding them. He offers the following:
1. A modified first cause argument. Philosophers from Aristotle to Aquinas and beyond had argued that all things we see have causes, and all those causes have other causes. The whole thing must start somewhere with an uncaused first cause. The uncaused first cause is God). Usually, the first cause argument is based on physical phenomena, and Descartes has this partially in mind. But he also applies the first cause argument to world of ideas, suggesting that the idea of God must come from God. All ideas have causes: they spring from other ideas that spring from other ideas. There must be a beginning to the generation of ideas--and that beginning is God. Indeed, there must be a beginning to everything: and that beginning must be that infinite source of being we call God.2. A modified argument from design. The argument from design suggests that the world is an orderly place. It follow from this that there must have been a force to set it in order. Sometimes, this is called the watchmaker argument. Something as complex as a watch implies an intelligent being behind it, and we can infer that there must be a watchmaker even without other evidence. Something as complex as world, must have a being much more intelligent than even the finest watchmaker behind it--and implies that there must be a God.
3. A modified ontological argument. An ontological
argument is one that says that
God, by definition, must exist. It begins with a definition of
God, e.g., St. Anselm's definition that God is
the greatest being you can think of. Descartes expands on this in
an interesting way. When I turn inward and look at my own
existence, he says,
I get a sense that I am not everything, that I am merely a part, and a
small part of something much greater, part of something that,
is infinitely greater. All have sense of this in terms of
world--and it's obviously true. But Descartes is talking about
something even larger, than the physical universe, what he calls
"infinite potentiality"--all that might be thought, all that might
be said, all that might be done. This, he says, is God--and, if
is how you define God, well--obviously he exists.
ORDER AND ASSURANCE?
But is all this helpful? For Descartes and some others, definitely yes--but there are a couple of problems, some things that make Descartes less helpful than he might be in providing assurance that what one believes is true.
1. Descartes proof is rather complex. It's not easy to follow, and even if you do follow, there seem to be some loopholes Descartes hasn't quite closed. Any proof of the type Descartes attempt must be flawless. If there is any error here, the whole thing collapses, and one suspects that there just might be a division by zero error here somewhere.2. The other problem is, that, even if Descartes's proof is valid, it doesn't prove very much. God exists? Fine. I've always suspected that he did. But what does that mean to me? What does that mean to my life? Descartes has not proved the existence of the God of Abraham, Isaac and Jacob. He has not proved the existence of a God who loves me and has a wonderful plan for my life. What he's proved is the existence of a philosopher's God--a concept, the concept of infinite potentiality. What he offers us is, in many ways, a typical mathematicians proof, and, for those who want something more--assurance about a God who cares about them--the man we talk about next has, perhaps, more to offer than Descartes. Next up: Blaise Pascal.