Full Idea
We always postulate a single form for each set of particular things, to which we apply the same name.
Gist of Idea
A Form applies to a set of particular things with the same name
Source
Plato (The Republic [c.371 BCE], 596a)
Book Reference
Plato: 'Republic', ed/tr. Waterfield,Robin [OUP 1993], p.345
A Reaction
This implies that the Forms have a great deal in common with the things, but also hints at the possibility of the Form being quite different from the particular things.