nature. Even Immanuel Kant, a noted father of political idealism and the liberal
institutional approach to world politics, echoes the dominant Hobbesian under-
standing of human nature.^27 In Perpetual Peace, Kant says, ‘The state of peace among
men living in close proximity is not the natural state; instead, the natural state is one
of war, which does not just consist in open hostilities, but also in the constant and
enduring threat of them.’^28 Kant believes that change is possible in world politics
but he nevertheless describes human nature as depraved:
Given the depravity of human nature, which is revealed and can be glimpsed
in the free relations among nations... one must wonder why the word right
has not been completely discarded from the politics of war as pedantic, or why
no nation has openly ventured to declare that it should be.Kant answers his own question when he says,
The homage that every nation pays (at least in words) to the concept of right
proves, nonetheless, that there is in man a still greater, though presently still
dormant, moral aptitude to master the evil principle in himself (a principle he
cannot deny) and to hope that others will also overcome it.^29In sum, Kant believes that it is possible to overcome our natural impulses, and
to create a system for perpetual peace. For Kant, the mechanisms of change are
inherent in ‘nature’; indeed, he says that peace is ‘insured[or guaranteed] by that
great artist nature’.^30 Specifically he proposes that the state of nature compels humans
to form political communities for their own protection. Those communities must
operate according to the rule of law. Reason dictates that the rule of law or right
will come to dominate. Further, the ‘growth of culture and men’s gradual progress
toward greater agreement regarding their principles lead to mutual understanding
and peace’.^31 And finally, Kant argues, that the ‘spirit of tradecannot coexist with
war’.^32 The mechanism for change is thus the interaction of the condition of war in
the state of nature and human reason which will understand the limits of war and
help humans create the mechanisms to overcome war and to achieve the rule of law
among nations.
Note the different emphases, due to their different assumptions about human
nature, that realists and liberals place on structure and agency. The realist and neo-
realist approach, emphasizing constancy, stresses constant structure, or in evolu-
tionary terms, a constant environment. The liberal approach, as I have described it
in Kantian terms, emphasizing change, stresses human agency in the form of reason,
as humans interact in and ultimately change structures. Not surprisingly, as Waltz
described them in Man, the State and War, the realist approach is more pessimistic
than the idealist approach.
Thus, although Waltz explicitly eschews a dependence on specific assumptions
about human nature in constructing a theory of international politics, he has (albeit
mostly implicitly) incorporated traditional realist assumptions about human nature
162 Rethinking ‘man’