Knowledge by acquaintance and description

The attempt to distinguish knowledge by acquaintance from knowledge by description is most closely associated with Bertrand Russell. The distinction is also crucial to one way of trying to develop a plausible foundationalist theory of justification and knowledge. According to Russell one can distinguish the two kinds of knowledge in terms of their respective objects. Put crudely, one has knowledge by acquaintance of things, and one has knowledge by description of propositions (representations of reality that are either true or false). But this crude characterization of the two kinds of knowledge is misleading. Russell also seemed to believe that one can have knowledge by acquaintance of properties and even facts (where a fact is a complex consisting of a thing’s exemplifying a quality or standing in a relation to another thing). The distinction, then, might be better put in terms of a kind of knowledge which has as its object something that is neither true nor false (knowledge by acquaintance) and a kind of knowledge which has as its object a bearer of truth value (knowledge by description).

According to Russell, all knowledge of truths ultimately rests on knowledge by acquaintance. The traditional foundationalist in epistemology holds that although I can know one truth by inferring it from something else I know, not everything I know can be inferred in this way. We can avoid a regress of knowledge by holding that at least some truths are known as a result of direct awareness of or acquaintance with those aspects of the world that make the corresponding propositions true.