idealist–materialist binary suggested in Wendt’s characterization of constructivism.
In developing a structural theory, Waltz devoted almost no attention to philo-
sophical matters. He simply declared that testing a theory should meet ‘philosophy-
of-science standards’ and assumed that positivist philosophy does the job.^7 Indeed
his stringently expressed positivism and tidy theory encouraged a later generation of
scholars, confronted with Continental social theory and philosophy, to pose post-
positivist philosophical challenges that Waltz found bewildering.^8 Nevertheless, his
treatment of structure brings a central philosophical issue to the fore: Are structures
real– really ‘out there’ in the world – even if they cannot be observed? Philosophical
realists set themselves against strong positivists andpost-Kantian constructivists on
this question. Realists alone will answer yes.
For all the importance of Waltz’s conception of structure, it is not, in my opinion,
well understood. Scholars have subjected it to intermittent, sometimes acute com-
mentary, but they have never made its most consequential features the centre of
attention. After Waltz presented his structural theory in the 1970s, he has not given
his critics a concerted response to their interpretations. Nor has he systematically
restated his position. I attempt to do so, however presumptuously, because I believe
Waltz’s philosophical stance is sounder than most of his critics claim, most recently,
from a realist point of view.
Philosophical realism is now in fashion among IR theorists.^9 That Waltz’s
stringently expressed positivism and a post-Kantian constructivism turn out to be
philosophical allies against philosophical realism many scholars will find an odd and
uncongenial claim. Waltz may find it so. As we shall see, there are many places where
he seems to undercut his declared position on theory by imputing objective properties
to system structure. In some instances he may simply have been careless. Cumula-
tively, they raise the possibility that he is an unreflective philosophical realist after all.
In substantiating these several claims, I divide this essay into six sections. The first
section traces Waltz’s view of political structure in his early work. The next section
recapitulates Waltz’s conceptualization of structure and its philosophical grounding.
The third section addresses the question of his (or any) theory’s relation to ‘reality’.
Waltz has drawn a line between theory and reality, only to subvert in it in a way
that any philosophical realist would applaud. The fourth section further illustrates
Waltz’s difficulty with structural theory and institutional reality. The fifth section
summons the ghost of Milton Friedman to confront two of Waltz’s critics.
The final section considers the vexing question of any theory’s fit to a world
already talked into existence. It shows how close Waltz has been to a stance,
grounded in post-Kantian constructivism, that solves his problem with theory’s
relation to reality and specifies the conditions under which any social theory
can make sense or use of the term structure. The chapter concludes on a speculative
note. Had Waltz come to appreciate philosophical differences among positivists,
realists and constructivists, he might better have guarded against the realist tendency
to find causal structures in the world. Had he seen the value in situating his structural
theory of international politics in an updated constructivism, our field might look
very different today.
90 Structure? What structure?