Breaking with the Near Eastern mythopoeic world-view, the Greeks developed rational thought and brought it to bear on the physical world and all human endeavor. Thus the Greeks laid the foundation of the Western philosophical and artistic traditions. The first theoretical philosophers appeared in Ionia. The earliest of these were the Cosmologists Thales, Anaximander, and Anaximenes, who argued that a particular imperishable substance underlay the structure of nature. Shifting emphasis from substance to form, Pythagoras asserted the primacy of mathematical relationships, and Parmenides proposed the eternal nature of the cosmos, a nature knowable through logical reflection alone. Democritus' atomic theory unified the Ionians' concern with substance and Parmenides' emphasis on reason. Influenced by the philosophers, Greek mathematicians systematized Near Eastern advances, and the school of Hippocrates broke the hold of mythopoeic thought on medicine. Rejecting speculation about the structure of the universe, the Sophists applied reason to human society in the effort to teach the skills of good citizenship. Radical Sophists developed a critical relativism, thus sparking an intellectual and moral crisis that shaped the thought of the three greatest Greek philosophers.

Attacking this relativism, Socrates argued that reason could reveal universal values by which people could live moral lives. However, his ideas and rigorous dialectical method disturbed many Athenians, who branded him a dangerous Sophist and forced him to commit suicide. Building on Socrates' ideas, Plato opposed to the imperfect material world a transcendent realm of Forms, contemplation of which would lead the rational mind to truth. The otherworldliness of this theory influenced later religious thought, but Plato extended it to the human world through his conception of the just state: critiquing Athenian democracy, Plato argued that the best state was one led by philosopher-rulers who governed absolutely yet selflessly according to universal moral principles. Aristotle synthesized the various strains of Greek thought, applying reason to data gathered through sense perception. Fascinated by many subjects, Aristotle analyzed ethics and politics, developing general principles of individual and social life through realistic appraisal of human nature.

The Greeks also brought the spirit of rational inquiry to the arts and history. Visual artists strove to represent nature and the human form both as it appeared to the eye and in accordance with universal, rational standards of beauty. Poets including Sappho and Pindar extended the philosophical interest in the individual by exploring human personality-its emotional life and yearning for excellence. Evolving from Dionysian ritual, Greek tragedy-exemplified by Aeschylus, Sophocles, and Euripides-examined human striving, using dialogue to present conflicts between heroic characters and the forces arrayed against them. Aristophanes turned comedy into an instrument of social criticism, attacking those he saw as undermining traditional Athenian values. The "father of history," Herodotus analyzed the Persian Wars, seeking to understand its causes by contrasting the opponents' cultures. Despite his rational analysis, Herodotus retained a myth-making turn of mind that Thucydides rejected in his history of the Peloponnesian War. Focusing on empirical evidence alone, Thucydides developed a fully rational theory of history and politics.

From the Greeks Western civilization inherited the concepts of political freedom and civic politics. The Greeks also passed to the West the principles of humanism and the basic forms of philosophical inquiry and artistic creation.