Arche (Ancient Greek: ἀρχή) is a Greek word with primary senses "beginning", "origin" or "source of action". (εξ’ ἀρχής: from the beginning, οr εξ’ ἀρχής λόγος: the original argument), and later first principle or element, first so used by Anaximander (Simplicius in Ph. 150.23), principles of knowledge (ἀρχαί) (Aristot. Metaph. 995b8). By extension, it may mean "first place, power", "method of government", "empire, realm", "authorities" (in plural: ἀρχαί), "command". The first principle or element corresponds to the "ultimate underlying substance" and "ultimate undemonstrable principle". In the philosophical language of the archaic period (8th-6th century BC), arche (or archai) designates the source, origin or root of things that exist. In ancient Greek philosophy, Aristotle foregrounded t