To affirm, that we paint them out to ourselves as extended, either resolves all into a false idea, or returns in a circle.

Extension must necessarily be considered either as coloured, which is a false idea; I or as solid, which brings us back to the first question.

We may make the same observation concerning mobility and figure; and upon the whole must conclude, that after the exclusion of colours, sounds, heat and cold from the rank of external existences, there remains nothing, which can afford us a just and constituent idea of body.
Add to this, that, properly speaking, solidity or impenetrability is nothing, but an impossibility of annihilation, as [Part II.Sect.

4.] has been already observed: For which reason it is the more necessary for us to form some distinct idea of that object, whose annihilation we suppose impossible.

An impossibility of being annihilated cannot exist, and can never be conceived to exist, by itself: but necessarily requires some object or real existence, to which it may belong.