232 A Positive Century (1815–1914)Th e two most prominent spokesmen of the common-will variant of posi-
tivism were Heinrich Triepel, from Germany, and Dionisio Anzilotti, from
Italy. Triepel was a native of Leipzig. He was not wholly, or even primarily,
an international lawyer but a constitutional lawyer as well. His infl uence in
international law in Germany, however, was im mense. He taught at the Uni-
versities of Leipzig, Tübingen, Kiel, and Berlin. Anzilotti— later saluted as
“that prince of positivism” — became one of the foremost fi gures in the
entire history of international law. He was from Tuscany and taught law at
the Universities of Florence, Bologna, Palermo, and Rome. He also served as
a legal adviser to the Italian foreign ministry and later became a long-
serving judge on the World Court.
Th e common-will variant of positivism placed its main emphasis on trea-
ties, but it did not deny the existence of customary law. It merely insisted that
customary law itself, properly understood, consists simply of agreements be-
tween states. Th e only diff erence is that customary rules are tacit agreements,
while treaties are written. In other words, there was an insistence that
customary law must be seen as contractual in character, in essentially the
same way that treaties are.
In the common-will version of positivism, there was comparatively little
stress on sanctions. Triepel was very careful to explain that the imposition
of a sanction is a separate issue from the presence of a binding rule of law.
Th is insistence on a separation of sanction from obligation is not surprising,
given the stress placed on express agreement as the source of legal obliga-
tion. A state that expressly agrees to accept an obligation can reasonably be
expected to carry it out. Th erefore, coercive mea sures to compel per for-
mance would be expected to play, at most, only a very marginal role.
Two especially distinctive features of this version of positivism should
be carefully noted. Th e fi rst is the positing of a sharp dichotomy between
two kinds of treaties: a “contract- treaty” (Ve r t ra g in German, or traité- contrat
in French), and a “law- treaty” (Ve re i n b a r u n g in German, or traité- loi in
French). A contract- treaty, as the name implies, is a mere contract and not a
true law. It is an arrangement between states to achieve some immediate,
specifi c, material goal. Th is is a treaty of the kind that Pufendorf had in
mind when he excluded treaties from the realm of true international law.
A law- treaty, in contrast, establishes a general rule of conduct that is in-
tended to remain in force for an indefi nite duration. It represents the common