René Descartes

1596 - 1650

René Descartes was a French philosopher, mathematician and a key figure in the scientific revolution. His work is considered as laying many of the foundations of philosophy, and his name is remembered in the cartesian coordinate system.

• Nationality

French

• Subject

Mathematics

• Fields

Analytical geometry, philosophy

• Distinctions

His town of birth has been renamed Descartes (previously La Haye en Touraine).

• Posts

While in the service of Duke Maximilian of Bavaria, Descartes visited the labs of Tycho Brahe in Prague and Johannes Kepler in Regensburg.

• Publications

Regulae ad directionem ingenii, c. 1623-1628, in Latin (Rules for the Direction of the Mind).

Meditations on First Philosophy, 1641, in Latin

Principles of Philosophy, 1644, in Latin.

Discours de la méthode, 1637, in Latin (containing 'Cogito ergo sum').

Les passions de l'âme, 1649, in Latin (Passions of the soul).

After his death, in 1663, the Pope placed Descartes' books on the Index of Prohibited Books.

• Laws

Of the 21 rules Descartes proposed in his Regulae ad directionem ingenii, 12 deal with scientific methodology.

In his Discours de la méthode, Descarte lays out 4 rules of thought. The first of these insists on verification of knowledge, a tenet of the modern scientific method.

• Theories

Cartesian coordinate system: a foundation to analytical geometry, which led to the discovery of infinitesimal calculus and analysis.

A founder of 17th century continental rationalism.

• Experiments/Discoveries

Observations of the link between atmospheric pressure and weather conditions, using a Torricellian mercury barometer.

Descartes' book Meditations on First Philosophy was published in 1641. In it he postulates Je pense, donc je suis (originally in French, but with the Latin Cogito ergo sum added, I think therefore I am). His work is still a standard text for philosophy students. As a forerunner to Spinoza and Leibniz, Descartes laid the foundation for 17th century continental rationalism, in opposition to the positions taken by Hobbes, locke, Berkeley and Hume.

Meditationes de prima philosophia 1641, René Descartes

Named in his honour, the cartesian coordinate system, arranging position in 3-dimensional space in relation to fixed orthogonal axes, is still the system used in geometry. He is considered to have been the founder of analytical geometry, a bridge between algebra and geometry, a vital step towards calculus and modern mathematics.

After his death, in 1663, the Pope placed Descartes' books on the Index of Prohibited Books, a vain attempt by the Church to stop rational thought and investigative methodology from challenging dogma and bigotry.

(Biographies of famous scientists no. 10)