12. Plato
Plato is possibly the most influential philosopher in all of Western thought. We know little about his early life except that he studied under Socrates, who encouraged him to think freely and to question everything around him. Plato went on to write about beauty, equality, justice, theology, political philosophy, cosmology, language, and epistemology (the study of how we can know things). He also founded the Academy, which became a model for education that led to the development of today’s schools. Additionally, he taught one of the other greatest thinkers in the history of the Western world, Aristotle.