Full Idea
There is no advantage at all in the admission of eternal substances, as in the Theory of Forms, unless there is among them a principle capable of moving something else.
Gist of Idea
There is no point at all in the theory of Forms unless it contains a principle that produces movement
Source
Aristotle (Metaphysics [c.324 BCE], 1071b11)
Book Reference
Aristotle: 'Metaphysics', ed/tr. Lawson-Tancred,Hugh [Penguin 1998], p.369