The Presocratics Part I: Thales, Anaximander, and Anaximenes

by melanchologist

Very little is known about the Presocratics, the loosely-defined group of ancient philosophers who, as one might imagine, predated Socrates and Plato.  The writings and alleged ideas of these philosophers are fragmentary, consisting mainly of anecdotal evidence from later philosophers and historians.  Many of these accounts may not even be entirely accurate, and much of the accounts themselves has been lost through the ages.  But what exists hopefully gives us a general idea of what the Presocratics believed, and stands as a testament of the movement away from the theological (as it relates to the ancient Greek gods) accounts of history, mankind, and the nature of things, towards argument, critical thinking, scientific inquiry, and metaphysical questions.

The first Presocratics came from Miletus, an ancient city in the greater region of Ionia, which is now the Western coast of Turkey.  Thales, who is thought to have been born in 625 b.c.e., is the earliest known Presocratic philosopher, and as such, is the first Western philosopher.  The ideas of Thales probably sounded as bizarre in Seventh Century Ionia as they do now.  He believed that water is the basic stuff of the universe, and that the earth floats on water.  He believed that the soul produces motion, and that since magnets move iron, then magnets must have a soul.  He is also said to have predicted a solar eclipse in 585 b.c.e.  While this is an extremely brief summary and oversimplification of what Thales believed, it is also basically all we know of Thales ideas.  However absurd they might seem upon initial reflection, they represent the earliest ideas about the physical properties of the cosmos without taking ancient Greek mythology and theology into account as explanations of natural phenomena.

Anaximander comes next in line as the second Milesian Presocratic philosopher.  He is thought to have been a pupil of Thales and is also said to be the the first individual to create a map of the world.  Anaximander also shares Thales’ belief in “material monism,” the idea that the cosmos is comprised of one single material stuff.  Significantly, Anaximander believed that water could not be the stuff of the cosmos, because water has its own unique character–its “wateriness.”  Rather, he believed that the stuff of the cosmos is indefinite or boundless (apeiron).  This indefinite “stuff” somehow gives rise to hot (fire) and cold (dark mist); furthermore, it is also always in motion.

The third and final Milesian Presocratic philosopher is Anaximenes, who was thought to be a pupil of Anaximander.  Anaximines also advocated the belief in material monism.  He believed that air was the stuff of the cosmos, and that it was also boundless (but not indefinite).  Anaximenes thought that air was transformed into all other substances in the universe through a vague process of condensation and rarefaction.

While each of these explanations is quite different from the others, they all represent an important turning point in the history of human ideas.  They represent the birth of metaphysics–the branch of philosophy that deals with understanding and explaining the fundamental nature of the world–the “essence” of things.  No longer would Homer and Hesiod’s accounts of the gods suffice as an explanation for how mankind and the world came into being.


Adamson, Peter.  History of Philosophy podcasts

Ancient Philosophy.  IEP archive

Cohen, S. M., Curd, P., & Reeve, C. D. C. (1995). Readings in ancient Greek philosophy: From Thales to Aristotle. Indianapolis: Hackett Pub. Co.

Sevenoaks  School.  The Presocratics