Full Idea
There are three elements in any given thing: the first is what the object actually is, the second is the definition of this, and the third is the name.
Gist of Idea
To grasp a thing we need its name, its definition, and what it really is
Source
Plato (The Laws [c.349 BCE], 895d)
Book Reference
Plato: 'Complete Works', ed/tr. Cooper,John M. [Hackett 1997], p.1552
A Reaction
I take the importance of this to be its distinction between what it is, and the definition of what it is. Aristotle maintains this distinction, but some modern Aristotelians seem to get the confused. Plato worried a lot more about names than we do.