Aristotle
Aristotle was a Greek philosopher and scientist whose writings on logic, biology, ethics, and politics laid foundational groundwork for Western intellectual thought for over two thousand years.
Aristotle studied under Plato at the Academy in Athens for nearly 20 years before later founding his own school, the Lyceum, where he lectured on an extraordinarily broad range of subjects.
He tutored the young Alexander the Great before Alexander's conquests, and his systematic approach to logic and the natural sciences, including detailed classification of plants and animals, influenced scientific thought well into the medieval period.
Aristotle's works were preserved and expanded upon by Islamic and later European scholars, and his ideas on ethics, politics, and rhetoric remain widely studied in philosophy departments today.