Plato was a theorist.
Philosopher . In the classical sense , a philosopher was someone who lived according to a certain way of life , focusing on resolving existential questions about the human condition , and not someone who discourses upon theories or comments upon authors . In a modern sense , a philosopher is an intellectual who has contributed in one or more branches of philosophy , such as aesthetics , ethics , epistemology , logic , metaphysics , social theory , and political philosophy . Plato ( [ ˈpleɪtoʊ ] Greek : Πλάτων Plátōn , [ plá.tɔːn ] in Classical Attic ; 428/427 or 424/423 -- 348/347 BCE ) was a philosopher in Classical Greece and the founder of the Academy in Athens , the first institution of higher learning in the Western world .