Full Idea
If the One moves it either moves spatially or it is altered, since these are the only motions.
Gist of Idea
The only movement possible for the One is in space or in alteration
Source
Plato (Parmenides [c.366 BCE], 138b)
Book Reference
Plato: 'Complete Works', ed/tr. Cooper,John M. [Hackett 1997], p.372