ABSTRACT
Thefield of political science is currently undergoing a newvariation of its perennial debates on whether and in what sense it is a “science,” how it should organize its inquiry into political life, and how it should build and justify its theories. On one side of this renewed debate, many political scientists have focused their work on championing one grand “ism” or another. The subfield of international relations as it is studied in theUnitedStates, for example, is largely organized around realpolitik “neorealism,” institution-centered “neoliberalism,” and sociologically informed “constructivism,” grand schools of thought that scholars have oftenmodeled either implicitly or explicitly in the style of either Kuhnian paradigms or Lakatosian research programs.1 On the other side, political scientists who focus on causal explanation via reference to causal mechanisms critique the paradigmatic “isms” as a constraint on understanding complex social and political phenomena.2 In this view, no single grand theory can capture political life, and the real explanatory weight is carried by more finely grained and contextual causal mechanisms. Political scientists increasingly theorize about path dependencies and complex interactions among the mechanisms emphasized by each grand “ism,” but we are still struggling to develop appropriate methods for making valid and cumulative inferences about such complex phenomena in settings that are in most instances observational rather than experimental. As Peter Hall has argued, the ontologies that political scientists posit in their theorizing about complexity have become disconnected from their methodologies.3
