“The attack on natural right in the name of history takes, in most cases, the following form: natural right claims to be a right that is discernible by human reason and is universally acknowledged; but history (including anthropology) teaches us that no such right exists; instead of the supposed uniformity, we find an indefinite variety of notions of right or justice. Or, in other words, there cannot be natural right if there are no immutable principles of justice, but history shows us that all principles of justice are mutable. One cannot understand the meaning of the attack on natural right in the name of history before one has realized the utter irrelevance of this argument. In the first place, “consent of all mankind” is by no means a necessary condition of the existence of natural right. Some of the greatest natural right teachers have argued that, precisely if natural right is rational, its discovery presupposes the cultivation of reason, and therefore natural right will not be known universally: one ought not even to expect any real knowledge of natural right among savages. In other words, by proving that there is no principle of justice that has not been denied somewhere or at some time, one has not yet proved that any given denial was justified or reasonable. Furthermore, it has always been known that different notions of justice obtain at different times and in different nations. It is absurd to claim that the discovery of a still greater number of such notions by modern students has in any way affected the fundamental issue. Above all, knowledge of the indefinitely large variety of notions of right and wrong is so far from being incompatible with the idea of natural right that it is the essential condition for the emergence of that idea: realization of the variety of notions of right is the incentive for the quest for natural right.”
— Leo Strauss in Natural Right and History (1953)
“It is important to emphasize that the lesson the students are drawing from their studies is simply untrue. History and the study of cultures do not teach or prove that values or cultures are relative. All to the contrary, that is a philosophical premise that we now bring to our study of them. This premise is unproven and dogmatically asserted for what are largely political reasons. History and culture are interpreted in the light of it, and then are said to prove the premise. Yet the fact that there have been different opinions about good and bad in different times and places in no way proves that none is true or superior to others. To say that it does so prove is as absurd as to say that the diversity of points of view expressed in a college bull session proves there is no truth. On the face of it, the difference of opinion would seem to raise the question as to which is true or right rather than to banish it. The natural reaction is to try to resolve the difference, to examine the claims and reasons for each opinion.”
— Allan Bloom in The Closing of the American Mind (1987)