Full Idea
So that our universe can resemble the perfect living creature in being unique, the universe was, is and will continue to be its maker's only creation.
Gist of Idea
The cosmos must be unique, because it resembles the creator, who is unique
Source
Plato (Timaeus [c.362 BCE], 31c)
Book Reference
Plato: 'Timaeus and Critias', ed/tr. Lee,Desmond [Penguin 1971], p.43