Aristotle is famous for:
1. His contributions to philosophy (critique of Plato's theory of perfect forms in which he observed that true reality exists in exactly in the physical existence Plato rejected; philosophy based on direct observation and experience rather than abstract thought and reasoning, etc.)
2. His contributions to biology and the scientific method (observation based conclusions, his method for classifying organisms)
3. His extensive writings on a wide variety of topics (including metaphysics, music, politics, and poetry)
and
4. His roles as the student of Plato and the personal tutor of famous leader Alexander the Great