Full Idea
Something is unlikely to be immortal if it's a compound, formed imperfectly from diverse parts.
Gist of Idea
Something is unlikely to be immortal if it is imperfectly made from diverse parts
Source
Plato (The Republic [c.374 BCE], 611b)
Book Reference
Plato: 'Republic', ed/tr. Waterfield,Robin [OUP 1993], p.367