INTRO:
Generalization last time that Bacon, Descartes, Pascal do an excellent job suggesting ways one might effectively pursue knowledge, that one who follows their methods can have a strong assurance that what he/she believes is true really is true. 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 revolution and put science on a much more stable footing than it had been before. But Bacon's method doesn't work for everything--in fact for things we care most about, no good at all. So not surprising that other 17th century thinkers looked for other means of obtaining certainty. One such
DESCARTES
French mathematician and philosopher (1596-1650). Rene Descartes one of most brilliant men who ever lived. Outstanding mathematicians--perhaps best in the world at the time. Invented analytic geometry (Cartesian coordinates), prepared way for Newton's calculus. Descartes also one of leading figures in science, as I'll explain later. But in some ways, most important contriubtion in field of philosphy. Two books: Discourse on Method/Meditations. In these books Descartes makes clear what he considers to be the best way of arriving at certainty.
Not from authority. Dissatisfied with what he had studied in school: special problems with conflicting authorities.
Not from experience. Much travel/many adventures: more you see, less sure you are of what's really true.
So where do you find certainty? By employing methods of mathematics: essentially, pure reason/deductive method.
Basic steps of method:
1. Accept nothing that can be doubted (only basic axioms)
2. Break a problem into parts
3. Proceed in an orderly way from simple to comples
4. Go back over proof to make sure nothing is left out (rigorous)
Advantages:
1. Great deal of certainty about answer
2. Anyone should be able to follow proof
Disadvantage:
1. Small error can lead to major problems.
x=y, w=z, a=1, b=2 (Given)
x=y (Given)
x+w=y+z
(x+w)(a-b)=(y+z)(a-b)
ax+aw-bx-bw=ay+az-by-bz
ax+aw-ay-az=bx+bw-by-bz
a(x+w-y-z)=b(x+w-y-z)
a=b
1=2
Where is mistake?
(My mistake was signing up for this class in the first place!)
2. Takes an enormous amount of time to prove anything worthwhile
(Your high school geometry classes!)
Provisional Rules:
1. Follow customs of country
2. Be resolute (story of me as kid not able to decide which way
to go around house).
3. Change self rather than fortune
4. Choose best occupation
Application of method to metaphysics:
1. Doubt all that can be doubted. Everything! I might be crazy! (No might about it, Art). Take nothing for granted at all.
2. One thing can't be doubted: I think. But in order to think, I must exist. Therefore, I know that I exist. (Cogito Ergo Sum: I think therefore I am. Woman's sweatshirt last year: I think, therefore I'm single.)
3. Next, I know that I have certain ideas. Ideas like: unicorns, hydrogen, square circles, dragons, shoes, God, interesting history teachers, oceans, water, myself. Don't know if any of these ideas represent things that really exist, but do know I have ideas. Anything more? Yes. These ideas seem to stand in certain relationships to each other. Some seem contingent on others.
4. Hydrogen, Water, Ocean/Shoes, shoemaker. If one knows oceans exist, it implies also existence of water, hydrogen, things on which ocean is contigent.
5. Consider relationship of God myself. One of these contingent on other? God w/o Art Marmorstein? Art Marmorstein w/o God? So--If an I, then God. But what do we know about me (we know your boring and that you tell stupid jokes). No--I know that I exist (cogito ergo sum). Therefore, god exists.
6. Many have some difficulty with this: but Descartes explains why. You are simply too used to trusting your senses. But, can you really put such faith in your senses? No--if there is no God, world might be a creation of of malevolent being who hates you (sort of like being in Mark Twain's Mysterious Stranger--absolutely horrifying book). All these wonderful things around you: just illusions: to make torment worse when all taken away.
7. Unless one knows that there is in charge of things an all-powerful
God who does not lie, we can never be sure that what our senses tell us
is real. But, if one does know that there is a truthful God in charge
of all things, one can trust one senses: God would not deceive us.
Does this mean we just believe things are whatever they appear to us to be? No. While God doesn't deceive us, we are limited and imperfect. As a result, we must do the kind of thing Bacon recommends, go out and investigate world around us systematically, using reason to help us come up with best understanding of data we collect. Interestingly enough, Descartes actually more successful than Bacon in exploration of physical world. 2nd part of Discourse on Method:
Application of method to physical world.
1. Circulation of blood
2. Copernican theory
In addition, using this method Descartes up with an entirely new theory of physics, which, if not as accurate as that of Newton later in the 17th century, still was much better than any other that existed at the time and served as the inspiration for two generations of French scientists.
All this quite impressive. If one has the patience, and follows Descartes step by step, you end up with certainty about existence of God, soul, reliability of senses--and with a method of investigating the natural world that seems to provide some solid results. Still, there's one major problem--one weak link in chain of proof.
My existence--to God's. 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, one of the central question in the Meditations--and Descartes does his best to show that the existence of God really cannot be doubted. He does this in a number of ways:
1. Modified first cause argument. (explain: Aristotle on through Aquinas: all things caused, all causes other causes, must start somewhere with an uncaused cause: God). Usually an argument based on physical phenomena: 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: spring from my other ideas or the ideas of others. Must be a beginning to ideas: God. Indeed, must be a beginning to everything: God.
3. Modified argument from design. (World is orderly, must be an orderer: watchmaker argument. Something as complex as a watch, must be intelligent being behind it. Something as complex as world, must have much more intelligent being behind it--again, usually thinking of physical phenomena, laws of physics. Descartes extends this also to realm of ideas, suggesting that the intellible (including both the material world and the world of ideas) requires an intelligence behind it.
3. Sustainer argument. Both argument from design/first cause old proofs for God's existence. Problem with such proofs is that they tend to leave God very distant. Starts everything, then steps out of picture. Not Descartes picture! Descartes argues that God not only started all, but continues to sustain it--without God, everything would immediately fall apart and cease to exist. Argument essentially that things depend not merely on antecedent causes, but on certain conditions right now. All things we depend on right now, depend on other things--ultimately on God.
4. Modified ontological argument. (Argument that says that God, by definition, must exist--begins with definition: usually God is greatest being you can think of). Descartes amplifies on this in an interesting way. When I turn inward, looks at my own existence, 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, ultimately, is infinitely greater. All have sense of this in terms of material world--and it's obviously true. But Descartes is talking about something larger, "infinite potentiality"--all that might be thought, all that might be said, all that might be done. This, he says, is God--and, if this is how you define God, well--obviously he exists.
But is all this helpful? For Descartes and some others, 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. Complex. 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 suspect that there just might be a division by zero error here somewhere.
2. The other problem is, even if 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 doesn't provide much in the way of answers here, but the next great thinker we'll talk about certainly did.
To Pascal lecture---