54 Law and Morality Abroad (to ca. ad 1550)kingdoms, on this thesis, possessed merely de facto power, which they had
somehow wrested from the grasp of the universal monarch. A prominent
champion of this theory was the eminent Italian Bartolus of Sassoferrato,
one of the most famous and learned lawyers of the Middle Ages. He lived in
the fourteenth century, teaching civil law (i.e., Roman law) at the Universi-
ties of Pisa and Perugia and also serving as a judge for some fi ve years. Bar-
tolus insisted that the Holy Roman emperor was, de jure, the ruler of the
whole world— even though, admittedly, this rule was not eff ective de facto
over large portions of the earth.
Th e best- known champion of the theory of universal imperial dominion
was not, however, a lawyer, but a famous literary fi gure from the generation
preceding Bartolus: Dante Alighieri of Florence, author of the Divine Com-
edy. His short work called De Monarchia (On Monarchy), written around
1314 (at about the same time as the Comedy), was a sort of manifesto of the
principle of po liti cal univeralism. “[U]nity seems to be the root of what it is
to be good,” he pronounced, “and plurality the root of what it is to be evil.”
On that basis, he contended that mankind constitutes a single society that
should be ruled “as one whole by one ruler.” And that ruler should be the
Roman emperor.
Dante’s vision was not, however, of a wholly monolithic global state. Th e
supreme world sovereign, he conceded, would not deal with “trivial deci-
sions in every locality.” Th e obvious reason was that “nations, kingdoms and
cities have characteristics of their own, which need to be governed by diff er-
ent laws.” Th e supreme ruler was therefore pictured as a kind of general
guardian of universal values, which transcended the local laws of the indi-
vidual states. “[M]ankind is to be ruled by [the supreme ruler],” Dante pos-
ited, “in those matters which are common to all men and of relevance to all,
and is to be guided toward peace by a common law.” Th e hope, then, was
that this universal rule would take the form of guidance from the supreme
monarch, which would be dutifully received and accepted by the various
national princes.
Even as Dante wrote, there was no serious possibility of his ambitious
dream being realized. Hopes for a unifi ed world, if they were to have any
chance of success, would have to take other forms. Two other alternatives
were on off er: a spiritual one in the form of the papacy and a legal one in the
form of natural law.