Putting Nature and Nations Asunder 151It would appear that Francis I had no legal scholars to defend his auda-
cious act of Realpolitik. Th e position was diff erent in the following century,
though, when the Dutch East India Company concluded an alliance with
the Muslim sultan of Johore against Portugal. Hugo Grotius forthrightly
defended this policy in his unpublished treatise De Indis. He regarded reli-
gious diversity as being of simply no relevance at all. Th e only thing that
mattered, in his opinion, was the justice of the cause in question. Th e fact
that (in Grotius’s view) the sultan was in the right, and the Portuguese in
the wrong, in the dispute at hand was all that was needed to justify the
alliance.
Natural Law and the Ius gentium— A Parting of the Ways
Th e various developments just identifi ed were indications of the ways in
which medieval modes of thought were steadily losing their hold in legal
thought and practice. Accompanying, and underlying, these changes were new
ways of thinking about the very nature of international law. Th e most out-
standing innovation, by a large margin, was a rethinking of the relationship
between natural law and its less- regarded ju nior partner, the ius gentium— an
innovation that would mark the birth of international law in its modern
sense. In a nutshell, what happened during the seventeenth century was a
loosening of the hitherto tight bond between these two kinds of law. Th ey
were not wholly divorced from one another— that would not occur until the
nineteenth century— but they were being fi rmly pulled apart and given clear
separate identities.
Th is came about as a result of the unsuitability of natural- law doctrine to
a world in which powerful central governments were emerging, based in
territorial states. In certain respects, to be sure, natural law was eminently
suited to serve as a basis of law between sovereigns. Since natural law was
radically cosmopolitan in character, it could, without any diffi culty, be held
to be applicable in the furthest corners of the earth, to every single kind of
human society. No law, surely, could be more truly international than that.
In other respects, however, natural law was profoundly ill equipped to deal
with practical questions of international relations. Th e reason is that natu-
ral law was, from its inception, always seen as basically a set of rules about