Pre-Socratic philosophy refers to the thought of ancient Greek philosophers who predated or were contemporaries, but not influenced by, Socrates. These philosophers, often called "physiologoi" or natural philosophers, explored a variety of topics from the natural world to human society, ethics, and religion, emphasizing explanations based on natural principles over those grounded in the supernatural.
Aristotle first distinguished these philosophers from their predecessors, the theologians and mythologists who attributed natural phenomena to divine intervention. Prominent Pre-Socratic philosophers were grouped into two categories: the Ionian group, led by Anaximander, and the Italiote group, led by Pythagoras.
While it's challenging to pin down the exact arguments presented by the Pre-Socratics due to the fragmentary nature of their surviving works, it's clear that they emphasized rationality over mythology. They posed essential questions about the nature of existence, the origins of things, the multiplicity of nature, and the possibility of describing nature mathematically. These foundational inquiries laid the groundwork for subsequent developments in philosophy, mathematics, and science.
The Pre-Socratics were chiefly concerned with the fundamental essence of the universe, the structure of the human soul, and the principles underpinning perceptible phenomena, human knowledge, and morality. Our understanding of their work is largely based on later philosophical writers and early theologians, as only fragments of their original writings survive.
Some of the prominent schools or approaches in Pre-Socratic philosophy include the Milesian school (which considered various natural elements as the foundation of everything), Pythagoreanism (which emphasized harmonious life based on numerical patterns), the Ephesian school (which explored the nature of philosophical inquiry itself), the Eleatic school (that advocated for the doctrine of the One), the Pluralist school (which argued for a plurality of substances), the Atomist school (that proposed an explicitly materialistic system of indivisible, imperishable atoms), and the sophists (who taught skills of debate and persuasion and believed thought rests solely on subjective impressions).
The impact of Pre-Socratic philosophy reverberated through subsequent eras, influencing thinkers from Socrates, who applied their methods of inquiry to human society, to modern philosophers like Hegel, Marx, Nietzsche, and Popper. Within the Marxist tradition, the Pre-Socratics are hailed as the original materialists, while Nietzsche and Popper saw them as important contributors to philosophical and scientific development.