Indeed, Waltz called himself ‘a Kantian, not a positivist’, although the context is
Kant’s Perpetual Peace, not theCritique of Pure Reason.^75 If Waltz had ever considered
fully the philosophical implications of his Kantian affinities, he might indeed have
acknowledged how close he is to an updated constructivism. Given Waltz’s stature,
we might wonder what his impact on the field would have been.
As it is, we take sides early on in our careers. We do so naively and unequivocally,
more or less as an act of faith. On one side are scholars with largely unexamined
realist commitments, positivist training and, in some cases, an irrational zeal for
rational choice theory, on the other scholars who dabble, too often indiscriminately,
in post-positivist philosophy and Continental social theory. Had Waltz gone
philosophical, the chasm would not have disappeared. On the contrary, the distance
between the two sides might have widened as scholars made a sustained effort to
defend their philosophical predilections.
If indeed the world is what we make it, post-Kantian constructivists are
necessarily relativists (recall Devitt’s characterization, quoted above). So are post-
positivists in general. Realists always invoke the correspondence theory of truth in
order to combat relativism with what they take to be common sense. ‘The
theoretical statements of a science are true or false’, as Rom Harré has put it, ‘by
virtue of the way the world is’.^76 Most positivists simply accept the common sense
view without further ado. Yet they need not repudiate relativism if they see truth
in Humean terms: at any given moment, systematically supported, provisionally
reliable inferences convey the truth as we know it.
Perhaps positivists would have ended up choosing sides. Perhaps the more
thoroughgoing among them could have mediated between realists and con-
structivists in the pursuit of knowledge, not truth. Perhaps both sides would have
tempered their contempt for the other. Perhaps not.
If Waltz had declared himself a thoroughgoing constructivist, other scholars
might have followed suit. There would have ensued a substantial, necessarily
inconclusive debate between realists and constructivists on the issues I have raised
in this chapter. Vacuous discussions of idealism and materialism might never have
arisen. A post-Wall generation of liberal internationalists might not be calling
themselves constructivists. Positivists and constructivists might have accepted their
differences on philosophical issues and come together to develop and elaborate
structural models of international politics, theories about institutions, agents and
motives and, not least, theoretical frameworks linking theoretical models of structure
and agency in larger social processes. Just perhaps.
Notes
1 I am grateful to Ken Booth, Harry Gould, Patrick Jackson, Patrick James, Jonathan Joseph
and Milja Kurki for their very helpful written comments and to the many members of
the audience in Aberystwyth for questions and comments. I am also grateful to Ken
Booth for suggesting a title better suiting this essay than anything I had in mind.
2 Kenneth N. Waltz, ‘Theory of International Relations’, in Fred I. Greenstein and Nelson
W. Polsby (eds),Handbook of Political Science, Vol. 8, International Politics(Reading, MA:102 Structure? What structure?