Full Idea
If we say "If day exists, lights exists", and then "day exists", and then "light exists", then parts of the judgement never exist together, and so the whole judgement will have no real existence.
Gist of Idea
If we utter three steps of a logical argument, they never exist together
Source
Sextus Empiricus (Outlines of Pyrrhonism [c.180], II.109)
Book Reference
Sextus Empiricus: 'Outlines of Pyrrhonism', ed/tr. Bury,R.G. [Prometheus 1990], p.132