Full Idea
Is there a single universe, or would it be more correct to speak of a plurality, even an infinite plurality, of universes? No, there can be only one, if it is to be created by the craftsman-god so as to correspond to its model.
Gist of Idea
Is there a plurality (or even an infinity) of universes? No, because the model makes it unique
Source
Plato (Timaeus [c.362 BCE], 30d)
Book Reference
Plato: 'Timaeus and Critias', ed/tr. Waterfield,Robin [OUP 2008], p.19
A Reaction
Democritus believed there was an infinite plurality of universes. Does this entail that there could only be one horse, and one thing of beauty, and one truth - to correspond to their Forms? Presumably not!