The Arche (the underlying stuff)

What is the one substance behind the many things we see?

The first philosophical question, asked around 600 BCE in Miletus: what is the arche – the stuff or source from which everything else comes? Thales said water; Anaximenes said air; Anaximander said an indefinite, boundless something. The answers vary; the question is the revolutionary part. To ask it is to assume something unheard of: the world is one thing wearing masks, and a mortal mind may pull the masks off without asking the gods' permission.