Presocratics

The pre-Socratics is a collective label for Greek philosophers who studied and wrote before Socrates, roughly from the 6th century BCE to the early 5th century BCE. They sought natural explanations for the world and its processes, challenging mythological accounts. Central to their inquiry were questions about the nature of reality, change, and knowledge. They introduced rational inquiry as a method, often focusing on a single underlying principle or on the arrangement of many substances. Because most of their writings survive only in fragments quoted by later authors, our understanding of their views is indirect and subject to interpretation.

Key figures and ideas vary across the tradition. The Milesians—Thales of Miletus, Anaximander, and Anaximenes—posed natural principles: water as the primary substance (Thales), the indefinite apeiron (Anaximander), and air (Anaximenes). Pythagoras and the Pythagoreans emphasized numbers, proportion, and harmony as fundamental to reality. Heraclitus held that everything is in flux, with fire often cited as the primary principle, while Parmenides argued for a single, unchanging being and denied real multiplicity and change. Zeno of Elea defended Parmenides with paradoxes illustrating the difficulties of motion and plurality. Empedocles proposed four roots—earth, air, fire, and water—governing phenomena through competing forces of love and strife. Anaxagoras introduced nous (mind or intellect) as a governing principle, and Democritus and Leucippus developed atomism, the view that reality consists of indivisible atoms moving in a void.

Their legacy lies in shifting inquiry from myth to rational explanation, laying groundwork for later metaphysics, science, and epistemology. The pre-Socratics influenced Aristotle’s and Plato’s analyses and helped shape the Western tradition of natural philosophy.