Full Idea
For some things, the cause of their necessity is something other than themselves, whereas for others there is no such external cause, but rather they are themselves the necessary cause of other things being the case. The simple is fundamentally necessary.
Gist of Idea
Some things have external causes of their necessity; others (the simple) generate necessities
Source
Aristotle (Metaphysics [c.324 BCE], 1015b14)
Book Reference
Aristotle: 'Metaphysics', ed/tr. Lawson-Tancred,Hugh [Penguin 1998], p.121
A Reaction
What is 'simple' is what terminates an explanation, and that is what-it-is-to-be each thing (its essence). The Greek view of necessity always seems to be a power to which we submit, rather than a passive state like true-in-all-worlds.
Related Idea
Idea 15108 Aristotle's says necessary truths are distinct and derive from essential truths [Aristotle, by Koslicki]