Near the beginning of The Idea of Human Rights, Michael Perry states that “One of my principal goals … is to clarify and address the unusually murky subject of ‘moral relativism’—and to do so from the perspective of what can properly be called ‘natural law.”” This he defines, following D.J. O'Connor, as a view according to which “basic principles of morals and legislation are, in some sense or other, objective, accessible to reason and based on human nature.” Subsequently, he explains that the relation between belief in natural law and in human rights is one of presupposition; that is to say, a doctrine of natural rights presupposes the moral realism which in his view is the central core of natural law theories.
As his discussion makes clear, Perry's claim that human rights presuppose a natural law should be understood as a theoretical claim. At the same time, it raises interesting historical issues. That is, when we examine classical accounts of the natural law, are these explicitly linked with doctrines of natural or human rights, or something recognizably similar? (Throughout this paper, I treat the terms “human” and “natural” rights as synonyms.) And more generally, what can we learn from the ways in which our forbears drew connections, or failed to do so, between a natural law and human rights?