170 Reason and Its Rivals (ca. 1550– 1815)from above, either from the precepts of a rich body of natural law or (as the
case may be) from the commands of a global sovereign.
On the whole, it is fair to say that the Hobbesian vision of international
order was indelibly marked by two crucial features. First, it was a world that
was intrinsically confl ictual rather than harmonious. Peaceful and orderly
relations between states were not impossible, but they had to be painstak-
ingly and consciously constructed by purely human initiative, from below.
Th ere might be islands of order, but they are protrusions from an ambient
ocean of confl ict, whether actual or potential. Th e second crucial feature of
the Hobbesian international world was that any orderliness must be entirely
treaty- based (although treaties did not necessarily have to be in the form of
written documents, with fancy lead seals). Th ere was no detailed body of
substantive natural-law principles to guide the statesmen of the world.
Th e “Grotians” versus the “Naturalists”
In the century or so aft er Grotius and Hobbes, the followers of the two
formed rival schools in international law. Th e followers of Hobbes were
known, somewhat confusingly, as the “naturalists.” Th eir signature doctrine
was the belief that natural law is the sole body of law that is binding between
states. Th eir opponents should most logically be labeled “dualists,” since
their defi ning belief was in the existence of two distinct bodies of law be-
tween states: natural law, and voluntary law or the ius gentium (depending
on the preferred choice of label). Th e historical pro cess, however, is oft en
weak on logic, with the result that this second school of writers have been
more commonly known as “Grotians” or alternatively as “eclectics.”
Th e Grotians
Th e Grotian, or dualist, school followed their eponymous forebear in hold-
ing international law to be a confederation between the two distinct bodies
of law: the law of nature and the law of nations (i.e., the voluntary law of na-
tions). Th e law of nature was not created, but found— or rather, deduced
from fi rst principles. Its content was determined by the nature of the uni-
verse, and man’s ability to discern it was given by reason. It contained no