René Descartes was a philosopher whose work, La Géométrie, which proves Pythagorean mathematics for without proof, it’s all theory.
Descartes’s brilliance was proving via algebra that geometry was a valid branch of mathematics. He was the first son, and third child to Joachim Descartes (1563-1640) and Jeanne Brochard (1566-1597). Joachim, the son of the medical doctor Pierre Descartes (1515-1566), who studied law and was a counselor in the Parliament of Brittany at Rennes. Jeanne was the daughter of the military man René Brochard (for whom her son was named) who was part of the garrison stationed at Poitiers. To read more about the man, go here; better yet, read the book.
- Bell, Eric Temple Ph.D Men of Mathematics, New York: Simon & Schuster, 1937, 529 pp.
- This is an excellent review of 34 of the greatest mathematicians from the ancient Greece to the end of the 19th century complete with biographies and a discussion of their work. Highly recommended.