The most vulgar philosophy informs us, that no external object can make itself known to the mind immediately, and without the interposition of an image or perception.

That table, which just now appears to me, is only a perception, and all its qualities are qualities of a perception.

Now the most obvious of all its qualities is extension.

The perception consists of parts.

These parts are so situated, as to afford us the notion of distance and contiguity; of length, breadth, and thickness.