Ancient Greek philosophy arose in the 6th century BC, marking the end of the Greek Dark Ages. Greek philosophy continued throughout the Hellenistic period and the period in which Greece and most Greek-inhabited lands were part of the Roman Empire. Philosophy was used to make sense of the world using reason. It dealt with a wide variety of subjects, including astronomy, epistemology, mathematics, political philosophy, ethics, metaphysics, ontology, logic, biology, rhetoric and aesthetics.[1]

Greek philosophy has influenced much of Western culture since its inception. Alfred North Whitehead once noted: "The safest general characterization of the European philosophical tradition is that it consists of a series of footnotes to Plato".[2] Clear, unbroken lines of influence lead from ancient Greek and Hellenistic philosophers to Roman philosophy, Early Islamic philosophy, Medieval Scholasticism, the European Renaissance and the Age of Enlightenment.[3]

Greek philosophy was influenced to some extent by the older wisdom literature and mythological cosmogonies of the ancient Near East, though the extent of this influence is widely debated. The classicist Martin Litchfield West states, "contact with oriental cosmology and theology helped to liberate the early Greek philosophers' imagination; it certainly gave them many suggestive ideas. But they taught themselves to reason. Philosophy as we understand it is a Greek creation".[4]

Subsequent philosophic tradition was so influenced by Socrates as presented by Plato that it is conventional to refer to philosophy developed prior to Socrates as pre-Socratic philosophy. The periods following this, up to and after the wars of Alexander the Great, are those of "Classical Greek" and "Hellenistic philosophy", respectively.

Main article: Pre-Socratic philosophy

The convention of terming those philosophers who were active prior to the death of Socrates as the pre-Socratics gained currency with the 1903 publication of Hermann Diels' Fragmente der Vorsokratiker, although the term did not originate with him.[5] The term is considered useful because what came to be known as the "Athenian school" (composed of Socrates, Plato, and Aristotle) signaled the rise of a new approach to philosophy; Friedrich Nietzsche's thesis that this shift began with Plato rather than with Socrates (hence his nomenclature of "pre-Platonic philosophy") has not prevented the predominance of the "pre-Socratic" distinction.[6]

Since 2016, however, current scholarship has transitioned from calling philosophy before the Athenian school "pre-Socratic" to simply "Early Greek Philosophy". André Laks and Glenn W. Most have been partly responsible for popularizing this shift in describing the era preceding the Athenian School through their comprehensive, nine volume Loeb editions of Early Greek Philosophy. In their first volume, they distinguish their systematic approach from that of Hermann Diels, beginning with the choice of "Early Greek Philosophy" over "pre-Socratic philosophy" most notably because Socrates is contemporary and sometimes even prior to philosophers traditionally considered "pre-Socratic" (e.g., the Atomists).[7]

The early Greek philosophers (or "pre-Socratics") were primarily concerned with cosmology, ontology, and mathematics. They were distinguished from "non-philosophers" insofar as they rejected mythological explanations in favor of reasoned discourse.[8]