After leaving the army in 1619, he visited an old classmate, Marin Mersenne, in whose cell he noticed a fly buzzing on the wall.
After leaving the army in 1619, he visited an old classmate, Marin Mersenne, in whose cell he noticed a fly buzzing on the wall. He came up with a new way of determining the fly's position using two lines from the side and below, which he later described more fully in an essay entitled Geography appended to his Discourse on Method. FTP name this French philosopher and mathematician known for his famous dictum "I think, therefore I am."
After leaving the army in 1619, he visited an old classmate, Marin Mersenne, in whose cell he noticed a fly buzzing on the wall.
René {Descartes}