Anaximander of Miletus, in the sixth century BCE, held that the first principle of all things is the apeiron, the unlimited and indefinite, from which opposites separate and into which they return, paying penalty to one another according to the order of time. It is among the earliest Greek ideas of an absolute.
Apeiron
The boundless: Anaximander’s indefinite, eternal source from which all things arise and to which they return.
Also: the boundless