Full Idea
Powers make a great part of our complex ideas of substances.
Gist of Idea
Powers are part of our idea of substances
Source
John Locke (Essay Conc Human Understanding (2nd Ed) [1694], 2.23.08)
Book Reference
Locke,John: 'Essay Concerning Human Understanding', ed/tr. Nidditch,P.H. [OUP 1979], p.300
A Reaction
This is quoted by Shoemaker, and is very important in modern thinking about properties and causation. I think it is a crucial idea, which got relegated into obscurity by Hume's unnecessarily ruthless empiricism.