Full Idea
The existence of things is to be known only from experience.
Gist of Idea
Existences can only be known by experience
Source
John Locke (Essay Conc Human Understanding (2nd Ed) [1694], 4.03.31)
Book Reference
Locke,John: 'Essay Concerning Human Understanding', ed/tr. Nidditch,P.H. [OUP 1979], p.562
A Reaction
This is the clearest statement you could wish for of the standard empiricist view of such things. Locke might take a broad view of experience, since he unshakably infers the existence of God from merely thinking about being.