This study, first published in 1984, presents an explanation and critical examination of the theories of Sartre, Heidegger, Husserl and Hegel on the fundamental relationships between persons. It also synthesizes the results into a new conception of one's relation to other people. Sartre's famous discussion of 'the Look' in his early treatise, Being and Nothingness, is the point of departure and central text. Since Sartre critically responds to his three famous predecessors, these thinkers are given an independent hearing. The book demonstrates various ways in which persons are internally related to one another, shows that one's access to other people typically does not compare unfavourably with one's access to oneself, and establishes the importance of a prior comprehension of the status of other people for an adequate treatment of knowing them.