Euclid

Euclid taught in Alexandria around 300 BCE and wrote the Elements, thirteen books that build the whole of ancient geometry and number theory from five postulates and a small set of common notions through explicit, checkable proof. Almost nothing is known of his life; even his working dates are inferred from the mathematicians who cite him. The Elements' axiomatic method, stating assumptions plainly and deriving everything else by logical proof rather than authority or observation, became the model later scientists and mathematicians measured rigor against, and the book remained a standard geometry textbook for over two thousand years.