Full Idea
We never have any impression that contains any power or efficacy. We never therefore have any idea of power.
Gist of Idea
We have no idea of powers, because we have no impressions of them
Source
David Hume (Treatise of Human Nature [1739], p.161), quoted by George Molnar - Powers 7.2.1
Book Reference
Molnar,George: 'Powers: a study in metaphysics', ed/tr. Mumford,Stephen [OUP 2003], p.114
A Reaction
[page in Selby-Bigges edn] It seems to me plausible that Hume is utterly wrong, because our own mental lives are a direct and constant experience of the physical powers and efficacies of material objects.