René Descartes: “I think; therefore I am”

René Descartes is considered by many to be the father of modern philosophy. He was born in 1596 in the small French town of La Haye, and his mother died during his first year. His father was an aristocrat who placed great importance on giving his children a good education. At eight years old, Descartes was sent to a Jesuit boarding school, where he would become familiar with logic, rhetoric, metaphysics, astronomy, music, ethics, and natural philosophy.

At twenty-two years old, Descartes earned his law degree from the University of Poitiers (where some believe he had a nervous breakdown) and began studying theology and medicine. He did not pursue them long, however, claiming he wanted to discover the knowledge that was found within himself or the world. He enlisted in the army, where he travelled and, in his spare time, studied mathematics. Descartes ended up becoming acquainted with famous philosopher and mathematician Isaac Beeckman, who was trying to create a method that could link physics and mathematics.

On the night of November 10, 1619, Descartes had three dreams, or visions, that would change the course of his life and philosophy. From these complex dreams, Descartes decided he would devote his life to reforming knowledge through mathematics and science. He began with philosophy because it was the root of all other sciences.

Descartes then began writing Rules for the Direction of the Mind, which outlined his new method of thought. The treatise was never finished—Descartes only completed the first of three sections (each composed of twelve rules). It was published posthumously in 1684.

Discourse on the Method

In his first and most famous work, Discourse on the Method, Descartes discusses the first set of rules that he created in Rules for the Direction of the Mind and how his visions made him doubt everything he knew. He then shows how his rules could solve profound and complex problems, like the existence of God, dualism, and personal existence (where, “I think; therefore I am,” comes from).

As Descartes continued to write, his fame grew. Descartes’s Meditations on First Philosophy, published in 1641, tackled the objections of those who disputed his findings in Discourse and introduced a circular form of logic known as a “Cartesian circle.” His Principles of Philosophy, published in 1644 and read throughout Europe, attempted to find the mathematical foundation of the universe.

While living in Stockholm, Sweden, to tutor the queen, Descartes died from pneumonia. Though he was a devoted Catholic, his work clashed with the church’s ideology, and after his death, his books were put on the Catholic Church’s index of Prohibited Books.