Full Idea
You cannot divide anything (such as the decad) into many parts, because as soon as you separate the first part, you are no longer dividing the original.
Gist of Idea
You cannot divide anything into many parts, because after the first division you are no longer dividing the original
Source
Sextus Empiricus (Outlines of Pyrrhonism [c.180], II.215)
Book Reference
Sextus Empiricus: 'Outlines of Pyrrhonism', ed/tr. Bury,R.G. [Prometheus 1990], p.168