Greek thinkers who were determined to seek the truth were often referred to as philosophers, a term that comes from the Greek word "philosophia," which means "love of wisdom." The ancient Greeks believed that wisdom, or knowledge and understanding, was the most valuable possession one could have, and they devoted their lives to seeking it. The philosophers of ancient Greece were some of the first people in history to systematically study and contemplate the nature of reality, the universe, and human existence. They sought to understand the world through reason and argument, and their ideas and writings have had a profound influence on Western philosophy and culture. Some of the most famous philosophers of ancient Greece include Socrates, Plato, and Aristotle.