The Milesian school, founded in the ancient city of Miletus in the 6th century BCE, is often credited with laying the foundation for Western philosophy. The three prominent philosophers of this school–Thales, Anaximander, and Anaximenes–challenged the mythological explanations of the world and sought to understand reality through reason and observation.
Thales, often recognized as the first philosopher, proposed that water is the fundamental substance (arche) underlying all things. He is famously quoted as saying, “All is water,” implying that the diversity of the world could be traced back to a single, unifying principle. Thales’ approach was revolutionary because it marked the shift from mythos to logos, from supernatural explanations to naturalistic inquiry.
Anaximander, a student of Thales, introduced the concept of the apeiron, or the “infinite” or “boundless,” as the origin of all things. He argued that the world is governed by a process of opposites–hot and cold, wet and dry–emerging from and returning to the apeiron. His work on cosmology suggested that the Earth was free-floating, unsupported by anything, a bold departure from earlier notions.
Anaximenes, another influential Milesian, returned to the idea of a single substance but identified air (pneuma) as the fundamental element. He proposed that different forms of matter arise from air through processes of rarefaction and condensation. Anaximenes’ contributions to the understanding of physical processes prefigured later scientific inquiries into the nature of matter.
The Milesian school’s legacy lies in its emphasis on rational thought and the search for natural explanations. These thinkers paved the way for subsequent philosophers to explore the nature of existence, reality, and the cosmos, without recourse to the supernatural. As Aristotle later reflected, “The principles of the Milesians were very simple, but they were bold enough to put forward a natural cause.”