Full Idea
If what we have stated either is the possible or something connected to it, there can of course be no question of its being true to say that x is capable of being but will not be. ...What is not but is capable of being either is or comes into being.
Gist of Idea
Anything which is possible either exists or will come into existence
Source
Aristotle (Metaphysics [c.324 BCE], 1047b05)
Book Reference
Aristotle: 'Metaphysics', ed/tr. Lawson-Tancred,Hugh [Penguin 1998], p.261
A Reaction
I'm a bit startled to find the great Aristotle spouting this nonsense. It's possible that every bird in England could simultaneously land in my home town, but it ain't never going to happen. Modern women could bear 50 children, but won't.