Most people, I imagine, have heard the name “Socrates.” If you ask someone to name a person with a big white beard, Socrates might come third after God and Santa Claus. Maybe fourth if you include Gandalf. And most of those people probably know he was a philosopher if nothing else.
Socrates, through his life and his student Plato (and subsequently Plato’s student Aristotle), influenced modern western thinking. His contributions to Greek philosophy became the foundation upon which western philosophy was built. Students of philosophy divide history by “pre-Socratic philosophers” like Thales and Heraclitus and everyone else who came after Socrates.