Plato (427-347 BC)

A Greek philosopher, pupil of Socrates and Aristotle’s teacher. Dealt with the nature of the universe; developed atomic theory of chemical change; ascribed geometric forms composed of bounding planes to the elements of earth, fire, air and water based upon their physical properties; held that elements could convert into one another through rearrangement of bounding planes; used deductive reasoning as a learning method.

Famous Quotes:

"Mathematics is like checkers in being suitable for the young, not too difficult, amusing, and without peril to the state."

"He is unworthy of the name of man who is ignorant of the fact that the diagonal of a square is incommensurable with its side."

See also: Aristotle, Socrates.