Full Idea
Simple ideas are not fictions of our fancies, but the natural and regular productions of things without us, really operating upon us. ...They represent to us things under those appearances which they are fitted to produce in us.
Gist of Idea
Simple ideas are produced in us by external things, and they match their appearances
Source
John Locke (Essay Conc Human Understanding (2nd Ed) [1694], 4.04.04)
Book Reference
Locke,John: 'Essay Concerning Human Understanding', ed/tr. Nidditch,P.H. [OUP 1979], p.564
A Reaction
Quoted by Jenkins to support her arguments for empirical knowledge being encoded in our concepts (which then produce a priori knowledge). I approve. This is the sort of realism in Locke which Berkeley and Hume shy away from.