Rene Descartes

René Descartes

Born: March 31, 1596 in France

Died: February 11, 1650 in Sweden

This one thing [analytic geometry] is of the highest order of excellence, marked by the

sensuous simplicity of the half dozen or so greatest contributions of all time to

mathematics. Descartes remade geometry and made modern geometry possible.

(E. T. Bell)

Rene Descartes was the third child of a well off noble family. His mother died a few days

after his birth, and he was a frail child. Because of this poor health, his father mostly

let René do as he wished, but at the age of 8 he was sent to a Jesuit "college" for formal

schooling in the classics. The rector of the school was sensitive to the boy's health and

allowed Descartes to stay in bed until he felt ready to attend class. Descartes used these

quiet mornings to think, and, later in life, he said that they were the real source of his

philosophy and mathematics.

By 18 Descartes was quite healthy, and he left school to begin leading the life of a

"gentleman" in Paris. He seems to have found wine, women and gambling amusing for awhile,

but he soon retired to a quiet suburb for 2 years to think. When his wilder friends

René Descartes

Born: March 31, 1596 in France

Died: February 11, 1650 in Sweden

This one thing [analytic geometry] is of the highest order of excellence, marked by the

sensuous simplicity of the half dozen or so greatest contributions of all time to

mathematics. Descartes remade geometry and made modern geometry possible.

(E. T. Bell)

Rene Descartes was the third child of a well off noble family. His mother died a few days

after his birth, and he was a frail child. Because of this poor health, his father mostly

let René do as he wished, but at the age of 8 he was sent to a Jesuit "college" for formal

schooling in the classics. The rector of the school was sensitive to the boy's health and

allowed Descartes to stay in bed until he felt ready to attend class. Descartes used these

quiet mornings to think, and, later in life, he said that they were the real source of his

philosophy and mathematics.

By 18 Descartes was quite healthy, and he left school to begin leading the life of a

"gentleman" in Paris. He seems to have found wine, women and gambling amusing for awhile,

but he soon retired to a quiet suburb for 2 years to think. When his wilder friends

finally found him, he decided to find another quiet place -- a war in Germany. On November

10, 1619 while the army was at its winter quarters near the Danube, Descartes had the most

remarkable "dream" in the history of science. He reported a number of episodes in the

dream, and one of them is usually believed to be the application of algebra to geometry

and the beginning of analytic and coordinate geometry. Descartes remained a soldier for

another 2 years and was even offered a lieutenant generalship. He then retired to Paris to

think about the problems of "What can we know?" and "How can we know it?" . His first

knowable fact was that of is own existence: "Cogito ergo sum." ("I think, therefore I

am.")

Until then Descartes had published nothing, but he had shared his discoveries and

philosophical conclusions with others. One of these, Cardinal De Berulle, convinced

Descartes that he had a sacred duty to share them with the world in writing, so he went to

Holland to think and write. He spent the next 20 years roaming around Holland and

corresponding with the brightest minds of Europe through the only person who knew his

whereabouts, Father Mersenne, an old friend from school and a mathematician. While he was

finishing his great book, Le Monde , he got word that Galileo had been forced to recant

the Copernican doctrine that the Earth revolves around the sun. Descartes now had a real

problem: like Galileo, he believed that the Earth revolved around the sun and used it in

his book, but he also believed that the Pope was infallible. His "solution" was simply to

not have La Monde published until after his death. But friends, including some influential

Cardinals, changed his mind , and Le Monde was published in 1637. A few theologians

10, 1619 while the army was at its winter quarters near the Danube, Descartes had the most

remarkable "dream" in the history of science. He reported a number of episodes in the

dream, and one of them is usually believed to be the application of algebra to geometry

and the beginning of analytic and coordinate geometry. Descartes remained a soldier for

another 2 years and was even offered a lieutenant generalship. He then retired to Paris to

think about the problems of "What can we know?" and "How can we know it?" . His first

knowable fact was that of is own existence: "Cogito ergo sum." ("I think, therefore I

am.")

Until then Descartes had published nothing, but he had shared his discoveries and

philosophical conclusions with others. One of these, Cardinal De Berulle, convinced

Descartes that he had a sacred duty to share them with the world in writing, so he went to

Holland to think and write. He spent the next 20 years roaming around Holland and

corresponding with the brightest minds of Europe through the only person who knew his

whereabouts, Father Mersenne, an old friend from school and a mathematician. While he was

finishing his great book, Le Monde , he got word that Galileo had been forced to recant

the Copernican doctrine that the Earth revolves around the sun. Descartes now had a real

problem: like Galileo, he believed that the Earth revolved around the sun and used it in

his book, but he also believed that the Pope was infallible. His "solution" was simply to

not have La Monde published until after his death. But friends, including some influential

Cardinals, changed his mind , and Le Monde was published in 1637. A few theologians