John

Descartes' Method of Doubt Biography Rene Descartes (1596-1650) Born in La Haye, a small town in Touraine, France. Educated at the Jesuit college Wrote Meditations Descartes is extremely important to Western intellectual history Contributions in physiology, psychology, optics, and especially mathematics Introduced analytic geometry Influential in modern scientific approach (can't just say it's true, show it's true) The Cartesian Method Descartes is very concerned with skeptical questions Though he was not actually a skeptic, he used skepticism as a method of achieving certainty. "I will doubt everything that can possibly be doubted, and if anything is left, then it will be absolutely certain. Then I will consider what it is about this certainty (if there is one) that places it beyond doubt, and that will provide me with a criterion of truth and knowledge, a yardstick against which I can measure all other purported truths to see if they, too, are beyond doubt." Doubt In order to doubt everything he could, Descartes used two conjectures Dream conjecture Evil demon conjecture Descartes was just as aware of how bizarre these ideas are as we areÐ'....that was his point, to doubt anything that had even the tiniest possibility to be false Cogito Ergo Sum Descartes realized that he could, in fact, doubt "absolutely everything, save one indubitable truth: I think, therefore I am" The self that doubts it's own existence must exist to be able to doubt Moreover, a self that doubts must not only exist, but must exist rationally (being a thing that thinks) The "Absolute" Once Descartes established that he doubted everything except that which cannot be doubted (his doubting)---he wanted a yardstick that he could measure all other things by to see if they are true beyond all doubt. This yardstick is clarity and distinctness Those things that are clear and distinct are true. What is clear and distinct? Mathematical concepts