Having covered the three great Greek philosophers of the 5th-4th centuries BC – Socrates, Plato, and Aristotle – it is time now to return to where it all began, with the “Presocratics”.
The Presocratics lived around the 6th and 5th centuries BC, and they are considered the first philosophers and scientists of the Western world.
One major obstacle in understanding these early Greek thinkers is that none of their writings has survived, and so we are dependent on later philosophers and historians to help us reconstruct what they taught.
Another problem is that it can be anachronistic to call what they were doing “philosophy”, in the modern sense of a subject separate from the natural sciences. The inquiries of the Presocratics covered a wide range of fields that included what we today would call “science.” But their inquiries laid the foundations for the work of Plato and Aristotle, and for that reason alone the Presocratics deserve to be called “philosophers.”
Also, unlike the writings of earlier generations such as the epics of Homer and Hesiod, the Presocratics did not try to explain the workings of the world by means of religious myths where the Olympian gods capriciously rule and intervene in human affairs. The Presocratics rejected this view and looked instead for purely natural explanations for the world’s origins and order.
One of the earliest Presocratic groups were the Milesians, who came from Miletus, a wealthy Greek city in Ionia on the west coast of modern Turkey. The three members of the Milesian School were Thales, Anaximander and Anaximenes, all of whom searched for what they called the archê – the most basic principle or element that would unlock nature’s mysteries.
The founder of the Milesian School was Thales. In his view, the archê of the universe was water, in the sense that the original state of the world was water and all things are made of water.
Thales’ successor and pupil was Anaximander, who argued that the original state of the world was not water but “to apeiron” – by which he meant some vast, eternal material that has no definite nature. Out of this indefinite material, everything that now exists arose.
The last of the Milesians was Anaximenes, who replaced Anaximander’s apeiron with air. According to Anaximenes, air is the source of everything and the substance out of which everything is made. When it is rarefied and condensed, air becomes other substances (such as fire and water), but in essence it is infinite and everlasting.
In this way the Presocratics initiated the study of nature as an ordered and intelligible system, which they called the “kosmos” and which they thought could be explained by a single and in some sense divine principle.
Dr. N. Trakakis, is a lecturer at the School of Philosophical, Historical & International Studies Monash University.