Full Idea
In order to form an idea of solidity, we must conceive two bodies pressing on each other without penetration. ..The ideas of secondary qualities are excluded, and the idea of motion depends on extension. This leaves us no just idea of solidity or matter.
Gist of Idea
We have no good concept of solidity or matter, because accounts of them are all circular
Source
David Hume (Treatise of Human Nature [1739], I.IV.4), quoted by Stephen Mumford - Dispositions 02.3
Book Reference
Mumford,Stephen: 'Dispositions' [OUP 1998], p.31
A Reaction
[compressed] For me these kind of strict empiricist arguments always recede when you accept the notion of an inference to be best explanation. We have some sort of notion of 'matter', but here the physicist seems to take over.