Human rights are rights which all persons equally have simply insofar as they are human. But are there any such rights? How, if at all, do we know that there are? It is with this question of knowledge, and the related question of existence, that I want to deal in this paper. 1. CONCEPTUAL QUESTIONS The attempt to answer each of these questions, however, at once raises further, more directly conceptual questions. In what sense may human rights be said to (...) exist? What does it mean to say that there are such rights or that persons have them? This question, in turn, raises a question about the nature of human rights. What is the meaning of the expression “human rights”? Within the limits of the present paper I cannot hope to deal adequately with the controversial issues raised by these conceptual questions. But we may make at least a relevant beginning by noting that, in terms of Hohfeld's famous classification of four different kinds of rights, the human rights are primarily claim-rights, in that they entail correlative duties of other persons or groups to act or to refrain from acting in ways required for the right-holders' having that to which they have rights. It will help our understanding of this and other aspects of human rights if we note that the full structure of a claim-right is given by the following formula: A has a right to X against B by virtue of Y. There are five main elements here: first, the Subject of the right, the person or persons who have the right; second, the Nature of the right; third, the Object of the right, what it is a right to; fourth, the Respondent of the right, the person or persons who have the correlative duty; fifth, the Justifying Basis or Ground of the right. (shrink)