(31/03/1596 - 1650/02/11)
French mathematician, scientist, and philosopher
He was born March 31, 1596 in La Haye, Touraine (France) in a family of officials.
The son of a Counsellor of the Parlement of Brittany. Her mother died a month after her birth, which inherited a fortune that allowed him to live with economic independence.
With eight years came at the Jesuit School of La Flèche in Anjou, where he would remain until the age of 16. Along with the typical classical studies Descartes studied mathematics and Scholasticism with the purpose of guiding human reason to understand Christian doctrine. He was influenced by Catholicism. At the end of his studies at the school, he enrolled in law at the University of Poitiers, earning the b.a. in 1616. However, never practiced the legal profession; in 1618 he entered the service of Prince Mauritius I of Nassau-Orange with the intention to follow the military career. Descartes served in other armies, but his interest always centered on the problems of mathematics and philosophy, to which he devoted the rest of his life.
He moved to Italy, where he stayed from 1623 to 1624 and went to France, where it would reside between 1624 and 1628. In this period, dedicated fully to the philosophy and to carry out experiments in optics. In 1628, after selling their properties in France, he went to Holland, where he lived in different cities, Amsterdam, Deventer, Utrecht and Leiden. It was then when he wrote philosophical essays, which was published in 1637. This consists of four parts: an essay on geometry, another about optics, a third on meteors and the last, the speech method, describing its philosophical speculations. This was followed by, among other trials, metaphysical meditations (1641; revised 1642) and the principles of philosophy(1644). The last volume was dedicated to Princess Elizabeth Stuart of Bohemia, who lived in the Netherlands and with which he maintained a great friendship.
He tried to apply to philosophy of inductive science, and in particular mathematics rational procedures. Before you configure your method, philosophy had been dominated by the Scholastic method, which was based entirely on comparing and contrasting the opinions of recognized authorities. Rejecting this system, Descartes established: "in our search for the direct route to the truth, not should deal with objects that we can not achieve a certainty similar to the demonstrations of the arithmetic and geometry. For this reason he doubted everything even have established reasons to believe. He left the first truth or Cogito, ergo sum, "I think, therefore I am". Starting from the principle that the clear consciousness of thinking proves his own existence, he maintained the existence of God. God, according to the philosophy of Descartes, created two classes of substances that constitute the whole of reality. A class was the substance thinking, or intelligence, and the other substance extensive, or physics. His philosophy, also known as Cartesianism, led him to develop complex and erroneous explanations of various physical phenomena. He approached the Copernicus theory of the universe, with its idea of a system of planets rotating moving around the Sun, he renounced this theory when it was considered heretical by the Catholic Church. Instead he devised a doctrine of vortices or whirlpools of Ethereal matter, in which the space was full of matter, in different States, by turning over the Sun.
His most important contribution to mathematics was the systematization of analytic geometry. He was the first who attempted to classify curves according to the type of equations that produce them, and also contributed to the development of the theory of equations. Descartes was responsible for the use of the last letters of the alphabet to designate the first letters to the known and unknown quantities. Also invented the method of the exponents (as in x 2) to indicate the powers of numbers. Moreover, formulated the rule, known as the law Cartesian of the signs, to decode the number of positive and negative roots of any algebraic equation.
In 1649 Descartes was invited to the Court of Christina of Sweden in Stockholm for the Queen to take philosophy courses. Everything seemed to go well if Cristina had not insisted on making to teach philosophy from five in the morning in a large, cold room. Descartes was too well educated to complain of this unpleasant circumstance, although I always hated the cold and rarely got up before noon. After three months of these horrific classes before dawn, sick of gravity and died February 11, 1650, a respiratory disease, which was probably pneumonia. Seventeen years later, his body returned to Paris, where he was buried.