THE time has now come to bring this long argument to a tentative conclusion. The validity of that conclusion can be tested only by the light which it throws upon the problem at issue. A great jurist of the last century who devoted his life to the historical study of law, once wrote that the undying spirit of natural law can never be extinguished. "If it is denied entry into the body of positive law, it flutters around the room like a ghost and threatens to turn into a vampire which sucks the blood from the body of law."1 The present essay is an attempt to account for the ghost and perhaps to exorcise it.
I suggested at the beginning of this enquiry that we should try to assess the meaning of natural law from two different angles, the historical and the philosophical. But on closer inspection these two lines of approach cannot but appear as fundamentally contradictory. The very notion of an "historical function" is hardly compatible with that of a "permanent value". History may well tell us the part which the doctrine of natural law has played in the building up of our cultural heritage. It may convince us of the importance of spiritual factors in the shaping of events and of positive institutions. But it will also make us painfully aware of the "relativism" of all natural law theories. It will provide the unfriendly critic with further grounds for dismissing such theories as typical "ideological superstructures" in the interplay and clash of historical forces.
Political ideology is the term which modern historians tend to substitute whenever natural law would formerly have been mentioned. From a strictly historical standpoint the two expressions may well seem equivalent. As the former Master of Balliol once pointed out, even the doctrine which, at the present day, most emphatically claims to be based on a "scientific" interpretation of history, can easily be construed into a theory of natural right.2 Yet, on the other hand, the____________________