Full Idea
Two of the key claims of empiricism are that all knowledge must be justified on the basis of experience, and that all knowledge in fact originates in experience.
Gist of Idea
Empiricism says experience is both origin and justification of all knowledge
Source
Georges Rey (Contemporary Philosophy of Mind [1997], 4.3)
Book Reference
Rey,Georges: 'Contemporary Philosophy of Mind' [Blackwell 1997], p.122