The classical philosophers and their philosophies timeline

Socrates believed that philosophy should achieve practical results for the greater well-being of society. He attempted to establish an ethical system based on human reason rather than theological doctrine. Socrates pointed out that human choice was motivated by the desire for happiness. Ultimate wisdom comes from knowing oneself. The more a person knows, the greater his or her ability to reason and make choices that will bring true happiness.

Plato is, by any reckoning, one of the most dazzling writers in the Western literary tradition and one of the most penetrating, wide-ranging, and influential authors in the history of philosophy. An Athenian citizen of high status, he displays in his works his absorption in the political events and intellectual movements of his time, but the questions he raises are so profound and the strategies he uses for tackling them so richly suggestive and provocative to educated readers.

Aristotle combines logic with observation to make general, causal claims. For example, in his biology, Aristotle uses the concept of species to make empirical claims about the functions and behavior of individual animals. However, as revealed in his psychological works, Aristotle is no reductive materialist. Instead, he thinks of the body as the matter, and the psyche as the form of each living animal, Though his natural scientific work is firmly based on observation.