228 A Positive Century (1815–1914)philosophy. It attained its position of dominance by way of gradual conver-
sion rather than sudden conquest.
An instructive demonstration of positivism’s incremental emergence into
its dominant role is provided by the American writer Henry Wheaton. His
principal early contribution to law had been as a reporter of the judgments
of the U.S. Supreme Court (from 1816– 27). Aft er this, he served as chargé
d’aff aires for his country in Denmark, followed by a long stint as ambassador
to Prus sia. In the course of this diplomatic work, he produced his Elements
of International Law (1836)— the fi rst systematic treatment of the subject by
an English- speaking writer. Th e book was a great success— comparable even
to that of Vattel— going into many editions, as well as being translated into
various foreign languages. It was in the pragmatic Grotian tradition, broadly
in the vein of Martens. It did not reject natural law on principle. Wheaton,
however, was willing to credit natural law with no greater role than as “a
remote foundation” of international law. “[T]he immediate viable basis” of
the subject, he stated, is “the customs, usages, and conventions [i.e., trea-
ties]” observed by states in their mutual relations. Th e spirit of positivism
was most evident in the way that the treatise was or ga nized. Wheaton’s very
fi rst topic was the sources of international law, in sharp contrast to Wolff
and Vattel, who had begun with long discourses on states and government
in general. Th e question of how international law is made was now assum-
ing a central position in legal writing.
Perhaps the fi rst major writer to take an overtly positivist stance was the
German scholar August Hefft er. Originally from Saxony, he became a pro-
fessor at the Universities of Bonn, Halle, and fi nally Berlin. Th e fi rst edition
of his treatise was written in 1844 in German. It was translated into French
and eventually extended to eight editions. He may fairly be regarded as the
fi rst true positivist writer in international law, in the sense of expressly de-
nying the existence (or at least the relevance) of natural law. Close on his
heels was an En glish writer named Richard Wildman, who insisted (in 1849)
that the precepts of natural law “can impose no legal obligation until they are
sanctioned by usage or legislative authority, and thus pass into law.”
One of the leading fi gures of the empirical tradition of positivism was the
Argentinian publicist and diplomat Carlos Calvo. Born in Montevideo in
present- day Uruguay, he was educated in Buenos Aires and then settled in
Brazil. Aft er the fall of the Argentine dictatorship of Manuel Rosas, he