Locke on Knowledge of Existence

The standard objection to Locke’s epistemology is that his conception of knowledge inevitably leads to skepticism about external objects. One reason for this complaint is that Locke defines knowledge as the perception of a relation between ideas, but perceiving relations between ideas does not seem like the kind of thing that can give us knowledge that tables and chairs exist. Thus Locke’s general definition of knowledge seems to be woefully inadequate for explaining knowledge of external objects. However, this interpretation and subsequent criticism ignore a special category of knowledge Locke calls “real knowledge”, which is Locke’s own account of how we can have knowledge of the real world. In in this paper I argue that real knowledge of substances requires that, in addition to the perception of a relation between ideas, there be a necessary connection between our ideas and the external objects they represent. It is because Locke thinks there is a necessary connection between these ideas and reality that he thinks the perception of ideas can give us knowledge of the actual world.