368 Between Yesterday and Tomorrow (1914– )More specifi cally, the Vienna School may be regarded as an in- depth ex-
ploration of the conceptual roots of the empirical version of positivism. One
indication of this was the important role that was assigned to sanctions. It
was insisted that a norm qualifi es as a true legal obligation if (and only if) a
breach of that norm exposes the actor, at least potentially, to a lawfully ad-
ministered sanction of some kind. A sanction is lawfully administered, in
turn, if the person imposing the sanction is legally empowered to do so. It
might be asked: empowered by whom? Th e answer was: empowered by some
greater authority. It may then be wondered: who grants that right of empow-
erment to the greater authority? Th e answer was: some authority that is
greater still. And so on. Except that Kelsen conceded that this chain of re-
sponses could not go on forever. Eventually, there must be some ultimate
authority who does not derive his own authority from a superior. Th is ulti-
mate authority is not, however, a sovereign ruler. Instead, it is a sovereign
norm, which Kelsen called the “basic norm” (Grundnorm).
Th e most important feature to appreciate about Kelsen’s basic norm is
that it was formal rather than substantive in nature. Th at is to say, it did not
dictate or determine the content of the law. Instead, it dictated the authority
by which the law was made. Th e content of the laws, he emphasized, cannot
be deduced, in the style of natural law, “by any intellectual operation.” It
can only be discovered empirically, by ascertaining what it was that the au-
thorized lawmakers have actually chosen to enact. In other words, accord-
ing to Kelsen, the substantive content of law is a product of will— that is, the
will of the persons possessing the authority to make law. On this point, Kelsen
was an orthodox positivist. But he contended that the authority to make law is
not a product of will. It is an emanation from the basic norm.
As to the actual content of the basic norm of international law, there was
room for disagreement within the Vienna School and its allies. Kelsen’s own
statement identifi ed it as “the general principle that we ought to behave in
the way that our fellow men usually behave and during a certain period of
time used to behave.” Put slightly more tersely, his basic norm was the
proposition that “international custom is a law- creating fact.” Th e basic
affi nity with the empirical variant of positivism is clearly apparent here.
Not surprisingly, there were some alternative suggestions for the exalted
status of basic norm. One of them came from an especially interesting source:
Anzilotti. He, in eff ect, reconfi gured his common-will theory along the lines