Aristotle
Plato's most famous student and the philosopher who tried to catalog everything — logic, biology, ethics, rhetoric, politics, poetry.
Origin
Aristotle (384–322 BCE) studied at Plato's Academy for twenty years, then founded his own school, the Lyceum. He tutored a teenage Alexander the Great. His writings — most of them lecture notes that survived by accident — became the operating system of medieval European and Islamic thought for over a thousand years. Where Plato pointed up toward abstract Forms, Aristotle pointed down at the dirt: classify the animals, count the constitutions, watch what people actually do.
Modern usage
His framework for persuasion ([[ethos-pathos-logos]]) still runs every rhetoric class. The 'golden mean' (virtue as the middle between two extremes) is a self-help staple. 'Aristotelian' as an adjective implies systematic, empirical, slightly pedantic — the foil to 'Platonic.'
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