144 Reason and Its Rivals (ca. 1550– 1815)Along with it, the idea of statecraft as a high art, with distinctive features of
its own, also advanced. Where the medieval manuals for statesmen— the
“mirrors of princes”— were designed to ensure that power was exercised
consistently with morality and religion, there now came to be more concern
that power be exercised so as most effi ciently to further the wealth and
power of the state. Utilitarian considerations, in short, were gaining ground
on moral, ethical, and legal ones.
Th ese trends had their eff ect on international legal thought and practice
in ways that have yet to be fully explored. Nevertheless, it is possible to sin-
gle out three developments that illustrate the postmedieval ethos with par-
tic u lar clarity. First was the emergence of a strong conception of state sover-
eignty. Second was a range of important changes in the law relating to
war— most conspicuously, the discarding of the principle of medieval just-
war doctrine that precluded a war from being just on both sides. Th ird was
the emergence of a new attitude to po liti cal and military alliances with non-
Christian states. Th ese developments formed the backdrop to the more gen-
eral ideas about the nature of international law itself that would be articu-
lated by Francisco Suárez and Hugo Grotius.Modern Conceptions of Sovereignty
Th e idea that corporate bodies, as such, could have rights under natural law
was not accepted in the Middle Ages. Corporate bodies were regarded as
mere “fi ctional” entities, whose very existence was a kind of gratuitous con-
cession on the part of the ruling authorities. Pope Innocent IV— that veri-
table prince of medieval canon lawyers— was most closely associated with
this doctrine. On this thesis, only a person could be a sovereign, and not a
state as such. In fact, the term “sovereignty” was a product of feudal law, at
the heart of which was the intensely personal, essentially contractual, rela-
tionship between lord and vassal. Only later, and gradually, did sovereignty
come to be attached to states as corporate bodies— with the implication of
state offi cials as stewards or temporary custodians of a corpus of ongoing
rights.
Two writers in the sixteenth century expressed this new outlook more
than any others. Th e fi rst was a Florentine scholar whose name would be-
come a byword for wickedness and immorality: Niccolò Machiavelli. Like