#cosmology definition

• Apeiron — A fundamental philosophical concept introduced by the pre-Socratic thinker Anaximander of Miletus, designating the infinite, indeterminate, boundless, and eternal primordial matter from which all things in the universe originate and into which they return. It represents the originating principle (arche) governed by an internal dynamic that generates opposites.
• First principle — A fundamental philosophical concept originating from Ancient Greece that designates the beginning, origin, first principle, or primordial substance from which all things derive and into which they eventually resolve. Structurally introduced by presocratic thinkers of the Milesian school, the term represents the ontological foundation of reality, explained variously through single cosmic elements like water, air, fire, or the indeterminate infinite.