Editing History of logic (section)

====Pythagoras====
[[File:Illustration to Euclid's proof of the Pythagorean theorem.svg|thumb|180px|Proof of the Pythagorean Theorem in Euclid's ''Elements'']]
Before 520&nbsp;BC, on one of his visits to Egypt or Greece, Pythagoras might have met the c.&nbsp;54 years older Thales.<ref>C. B. Boyer (1968)</ref> The systematic study of proof seems to have begun with the school of Pythagoras (i. e. the Pythagoreans) in the late sixth century BC.<ref name="Kneale3"/> Indeed, the Pythagoreans, believing all was number, are the first philosophers to emphasize ''form'' rather than ''matter''.<ref>{{cite book |page=11 |author=Samuel Enoch Stumpf |title=Socrates to Sartre}}</ref>