384 – 322 BC

Line engraving of Aristotle by P. Fidanza after Raphael Sanzio The founder of formal logic, Greek philosopher Aristotle (384–322 BC), was also an astounding scientist, who pioneered the study of zoology. Indeed, his scope of intellect ranged from ethics to aesthetics, logic and biology and everything in between. He enrolled in Plato’s Academy when he was 17 and devoted his entire life to study. After Plato’s death, Aristotle went on to be the private tutor to Alexander the Great for at a time, and then, with Alexander’s permission, built his own academy in Lyceum.

At the school, Aristotle was known to lecture while walking about the campus, which gave rise to his students being dubbed, “Peripatetics,” or those who travel from place to place. The school housed one of the most impressive libraries of the ancient world, and offered open and free lectures to the public.

Christian scholasticism and Medieval Islamic philosophy were rooted in Aristotle’s philosophical and scientific systems. He formalized universal principles of logic that used deduction and inference to form logical arguments, his most famous being syllogism.

Despite only 31 of his 200 manuscripts remaining today, Aristotle’s legacy remains immeasurably far-reaching as his arguments touched on almost every aspect of human knowledge, and philosopher’s continue to debate, interpret and teach his principles.