What Is It to Know Someone?

Ordinary language makes a distinction between knowing a person by having seen her before and knowing her “personally,” that is, by having interacted with her. The aim of my paper is to substantiate this distinction between knowledge by interaction and knowledge by acquaintance, that is, knowledge acquired by way of the senses. According to my view, knowledge of a person by interaction is the kind of knowledge sustained by addressing her as “you.” I claim that this second-person knowledge is essentially of the same form as first-person knowledge, which is knowledge sustained by the capacity to use the first-person pronoun, “I.” Both are species of what I will call, in a Kantian manner of speaking, knowledge from spontaneity. In knowing each other as “you” and “I,” two persons united in a second-personal interaction are and spontaneously know each other as the joint subject of their act. Hence knowledge by interaction—the kind of knowledge which grounds the everyday conception of knowing someone “personally”—is necessarily shared. To say that A knows B in this manner implies—in fact, it is the same thing as saying—that B knows A, it is to say that A and B know each other. This is what constitutes knowledge by interaction as a sui generis kind of knowledge of persons.