Full Idea
Our basic description of the universe contained an intelligible and unchanging model, and a visible and changing copy of it.
Gist of Idea
The universe is basically an intelligible and unchanging model, and a visible and changing copy of it
Source
Plato (Timaeus [c.362 BCE], 48e)
Book Reference
Plato: 'Timaeus and Critias', ed/tr. Lee,Desmond [Penguin 1971], p.67