Rene Descartes (1596-1650) (France)

Like the ancient Greek philosopher Socrates, Rene Descartes used questions to find truth. He questioned everything including his own existence. "If you would be a real seeker after truth, it is necessary that at least once in your life you doubt, as far as possible, all things." He proved that he existed with the statement, "I think therefore I am." Because he could think, he must exist. Descartes used "hyperbolic doubt", a method of reasoning that stated that though he may doubt, he cannot doubt that he exists.

Descartes was a scientist at heart and used science to explore his ideas. He set out to trust only that which is clearly and distinctly seen to be beyond any doubt. Anything that could be doubted was rejected. This included God and the teachings of the church. He believed that he could not trust his senses, because distance can distort what you see. He came to the conclusion that he could only trust mathematics because, awake or asleep, two plus three always equals five.

By use of this scientific reasoning, Descartes decided that reality is made up of two separate things: mind (thinking) and body. After establishing that he existed, he spent the rest of his life trying to prove how minds and bodies work together. In the end, he concluded that the body was like a machine connected to the mind by a small gland in the brain.

Eventually, Descartes moved from France to Holland because the Church was persecuting scientists, such as Galileo, and he wanted to be free to continue his work. Later he was invited to Sweden to teach the Queen. While there, he caught pneumonia and died.

Classroom discussion questions:

How would Descartes answer the question: "Which is more powerful, love or hate?"

How would Descartes define truth?

Besides math, what school subject(s) would Descartes have most valued and why?

Why was it so important to Descartes to first prove that he exists?

To learn more about Rene Descartes, follow these links:

http://www.utm.edu/research/iep/d/descarte.htm

http://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Descartes.html

http://serendip.brynmawr.edu/Mind/Descartes.html

http://www.maths.tcd.ie/pub/HistMath/People/Descartes/RouseBall/RB_Descartes.html

http://es.rice.edu/ES/humsoc/Galileo/Catalog/Files/descarts.html

http://www.lucidcafe.com/library/96mar/descartes.html

http://philos.wright.edu/DesCartes/Meditations.html