Descartes and the Dawn of Rationalism

Descartes began his work during this period of radical upheaval where the monolithic authority of the church had collapsed. The medieval systems of the guilds had collapsed. The political structures of Europe had changed. And, it was a very unsettling period for many folks. Because, in the most part while the church was dominating things, and had the monolithic authority that it enjoyed, people were content to get their questions answered by the dictates of the church. [00:04:35]

Descartes stepped into this situation of confusion and skepticism and he said I wanted to find certainty. "I want to have a knowledge of truth that I can rely on without being open to the vagaries of public opinion." And, being a student of mathematics, he was trying to find truths that were as certain to him as the conclusions that could be reached doing the work of math. [00:06:53]

He said that the method of searching for truth involves two elements: intuition and deduction. Now, I have to pause here because when we talk about the term "intuition," we liken it to some kind of imaginative sense or a hunch, or the thing my wife expresses when we disagree and I try to give a reason for my position and she says, "What good is that? I have an intuition." And it's over. [00:08:17]

The idea that he's using -- the way in which he's using the word 'intuition' is to describe a rational concept -- a rational idea that is so clear and so distinct that it is manifestly undeniable. So, what he was looking for -- what he was calling 'clear and distinct ideas.' So, that once you have those axioms, or those basic primary truths -- that to doubt them is to affirm them. [00:08:47]

The second part of his method is the application of the principles of deduction. When we talk about deduction, we talk about deducing conclusions from premises, and which conclusions follow necessarily from the premises. When we talked about Aristotle's delineation of the science of logic, you will recall that he saw that the first element of logic was the law of non-contradiction. [00:09:26]

Descartes was not satisfied with reaching possible inferences. He wanted to construct a method of knowing that was based, first of all, on the clear and distinct ideas -- those necessary truths like the law of non-contradiction; and on the necessary inferences that could be made from those primary truths. Let me read a state from his Discourse on Method, where he says this: "In the subjects we propose to investigate, our inquiries should be directed not to what others have thought, nor to what we ourselves conjecture, but to what we can clearly behold and with certainty deduce." [00:13:45]

He embarked on this process where he doubted everything. But the one thing he couldn't doubt was that he was doubting. Because, if you doubt that you're doubting, what are you doing? You're doubting. So, one thing I know for sure is that I am doubting. If I doubt that I am doubting, I prove that I am doubting. Because, to doubt doubt requires doubt. So, he came to the certain conclusion that he was doubting. [00:18:17]

Well, for someone to doubt, they must be thinking. Because doubt is a form of thinking. You can't have doubt without thought. Because, doubt is an element of thought. So, now he says, "If I am doubting, then I know that I am thinking. Now, if I am thinking, what else does that tell me through resistless logic? If I am thinking -- I am having thought, there must be something that is doing the thinking, because thought requires a thinker. [00:19:09]

And, if I am thinking, and I am doubting, I must be." So, he gives us his famous formula that we have all heard at one time or another, pronounced variously by different people, and I am going to give you this pronunciation, "Cogito Ergo Sum." Now, perhaps the most important part of this formula is the middle word: ergo, which means what? It means therefore. It is the word, which signals a conclusion -- a rational conclusion. [00:20:22]

It is very important to understanding rationalism that the starting point for all rational investigation now is self-consciousness. That's where it starts. And, according to Descartes it's the only place it can start. It can't start with your consciousness -- at least it can't start with your consciousness for me. It can't start with God's consciousness. God can start with God's consciousness. [00:21:22]

So, that for Descartes the starting point of all philosophical investigation is with the self. It doesn't mean that's where you end. But that's where you start -- with self-consciousness. Now, we're going to look in our next session about some of the implications of this, and some questions that may be raised about it, and have been raised about it. [00:22:30]

For now we understand why in the midst of all this skepticism, and all this confusion, Descartes sought an undeniable absolutely certain starting point for the reconstruction of knowledge. [00:23:01]