Great Ideas of Philosophy

Lecture Twenty-SixDescartes and the Authority of ReasonScope: René Descartes (1596–1650) is one of the fertile minds in the history of ideas. He discovered analyticalgeometry, was an important contributor to the physical sciences, and was perhaps the most important figurein that branch of philosophy called philosophy of mind.Like Bacon, he was in search of a reliable method. He was alive when Bruno was burned at the stake(1600) and an accomplished scholar when Galileo was called before the Inquisition (1633). He was wellaware of the superstitious excesses of the “natural magic” group that dominated Renaissance science.Then, too, always fashionable forms of skepticism and vulgar materialism were enjoying the usualfollowing.In his deliberate, rather geometric fashion, Descartes sought an axiomatic method of proof capable of bothestablishing incontrovertible propositions and defeating radical skepticism. His commitment was to acceptno product of his own thought until it reached a level of clarity and indubitability that could not bereasonably challenged.OutlineI. The philosophical power of Descartes is a matter of record. In some accounts, the modern period of philosophyis said to begin with Descartes (1596–1650). His was among the most fertile imaginations in the scholar’spantheon. He is the recognized founder of analytical geometry and made important contributions to optics andphysiology.A. Descartes’s mother died within a year of his birth. The grandmother who then took responsibility for himpassed on when Descartes was 10 or 11.B. On his grandmother’s death, Descartes was enrolled in the new Jesuit school at La Fleche, where heremained for nine years. During this time, he was also in regular correspondence with the leading lights ofthe European intellectual and scientific community and was seen by them as a force to be reckoned with.C. He earned a law degree at Poitiers and, at the age of 22, fought as a mercenary in the Dutch army’s war ofindependence against Spain. This service introduced him to a prominent Dutch mathematician, IsaacBeeckman, who encouraged Descartes to compose a mathematically based treatise on music.D. In 1619, while serving as a mercenary in the army of the Duke of Bavaria, Descartes had three vividdreams, which he took to be a summons to create an original and daring path to knowledge, a mirabilisscientiae fundamenta.II. What Descartes finds in the Scholastic lessons of his early schooling is a logical rigor with no power ofdiscovery. Renaissance “science” is merely dogma posing as knowledge. Thus, like Bacon, Descartes looks fora method of scientific discovery. He summarized his method in two monumentally influential works, publishedfour years apart: Discourse on Method (1637) and Meditations on First Philosophy (1641).A. Diversity of opinions and tendency toward error arise not from unequal or insufficient rational power butfrom faulty methods of inquiry and discovery. Every factual claim grounded in perception is subject todistortion.1. The study of history removes one from the very context in which the demands for knowledge are mostinsistent. No two historical events are ever precisely the same, and all that can be gleaned from thatkind of inquiry are generalities subject to interpretation.2. Philosophy doesn’t have a single method; the great philosophers of history scarcely agree with oneanother on any major point.3. Mathematics can formulate indisputable truths at a certain level of abstraction but cannot be a methodof discovery.B. It is the purpose of the Discourse on Method to reveal how Descartes has fashioned a mode of inquirydesigned to save himself from error. For him, the right method begins with an utterly skeptical position anda profession of ignorance.4©2004 The Teaching Company Limited Partnership