This paper explores two related issues concerning Locke’s account of epistemic justification for empirical knowledge. One issue concerns the degree of justification needed for empirical knowledge. Commentators almost universally take Locke to hold a fallibilist account of justification, whereas I argue that Locke accepts infallibilism. A second issue concerns the nature of justification. Many (though not all) commentators take Locke to have a thoroughly internalist conception of justification for empirical knowledge, whereas I argue that he has a (partly) externalist conception (...) of justification: it is the fact that sensation is caused by an external object that justifies our belief in the corresponding object. So, while most commentators take Locke to be a fallibilist with an internalist conception of justification for empirical knowledge, I argue he is actually an infallibilist with an externalist conception of justification. (shrink)