Full Idea
Without oneness it is impossible to conceive of many.
Gist of Idea
Without oneness we can't conceive of many
Source
Plato (Parmenides [c.366 BCE], 166b)
A Reaction
This is the culmination of a long discussion of the nature of the One (of Parmenides), so it ties that concept to the standard Greek idea that counting, and hence all of arithmetic, is grounded in the concept of a unit. Primitive processes?
Book Reference
Plato: 'Parmenides', ed/tr. Gill,M.L./Ryan,P. [Hackett 1996], p.175