Aristotle

Aristotle developed the first formal system of logic, including syllogistic logic, in his work 'Organon'. He identified the rules of valid reasoning, such as the syllogism, which became the foundation of Western logic for over two millennia.

Philip II of Macedon invited Aristotle to tutor his son Alexander. Aristotle taught Alexander for several years, instilling in him an interest in Greek culture, science, and philosophy. This relationship influenced Alexander's later policies of Hellenization in his conquered territories.

Aristotle wrote the 'Nicomachean Ethics', a treatise on virtue ethics. He argued that the highest good is eudaimonia (flourishing) achieved through virtuous activity and practical wisdom. This work became a cornerstone of Western moral philosophy.

Aristotle founded the Lyceum, a school in Athens dedicated to philosophical and scientific research. He established a library and organized systematic studies across disciplines. The Lyceum became a major center of learning, rivaling Plato's Academy.

After Alexander's death, anti-Macedonian sentiment rose in Athens. Aristotle, associated with Macedon, left the city to avoid persecution, saying he would not allow Athens to 'sin twice against philosophy' (referring to Socrates' execution). He died in exile in Chalcis.