 It is tempting to suppose that Russell equivocates between the relation of acquaintance and the special kind of knowledge of truth (foundational knowledge) whose sole source is acquaintance. That we ordinarily talk about knowing things and people might encourage this equivocation. Moreover, perhaps the fact that acquaintance is a form of awareness of the most direct, most secure kind, and is fundamental to all knowledge of truths, led Russell to think it deserves to be called “knowledge” of the thing in question. The issue here is largely terminological. In order to guard against confusing acquaintance on the one hand with foundational knowledge of truths acquired by acquaintance on the other, and facilitate an examination of the relation between them, we should be more careful than Russell and restrict knowledge by acquaintance to foundational knowledge of truths. By contrast, one can have acquaintance with items that are not truths, items that cannot be said to be true or false. Knowledge by description, on the other hand, is nonfoundational knowledge of truths; it “always involves…some knowledge of truths as its source and ground” (Russell 1912: 72–3). We adopt this usage in what follows. 