Descartes …

• Rene Descartes (1596-1650) stands out strongly among philosophers in the height of the Newtonian era of science.
• Like Newton, he reasons that you can reduce all laws of nature to pure equations and numbers.
• This is opposite to saying that nature's contents have number and equations everywhere within her. Reductionism breaks nature up into parts that are explained by numbers.
• Descartes was an excellent philosopher - but he was also an excellent physicist, mathematician, and physiologist. So he knew science, number, and the body.
• He strongly departed from Aristotle's ideas and from the marriage of science and the belief that every part of nature has to do with higher beings.
• He did not agree with Plato's existence of the soul.
• Descartes said, "Cogito ergo sum". This means that "I think, therefore I am." This is important. He is saying that a human knows itself to be real when thinking.
• Descartes courageously doubts his senses as trustworthy. He then peels away everything that he can doubt. At last he is left only with his ability to doubt. So he only sees his doubting thought - and claims that the thng that is doing the doubting must exist and must in fact be ... himself.
• Opponents of Descartes say that he missed the truth. They say that while he sees himself doubting - he is not the doubting thought. He is that which watches the doubting - he is that which watches the thought.