Constructivists might respond that Moravcsik privileges rational-choice explanations and sets a higher standard for constructivist hypotheses (since rational-choice scholars typically do not attempt to test their own hypotheses against competing constructivist formulations). Many ‘post-positivist’ scholars, moreover, dispute Moravcsik’s image of EU studies as ‘science’, with its attendant claims of objectivity and of an objective, knowable world. For such scholars, Moravcsik’s call for falsifiable hypothesis-testing appears as a power-laden demand that ‘non-conformist’ theories play according to the rules of a rationalist, and primarily American, social science (Jшrgensen 1997: 6-7). To the extent that constructivists do indeed reject positivism and the systematic testing of competing hypotheses, the rationalist/constructivist debate would seem to have reached a ‘metatheoretical’ impasse-that is to say, constructivists and rationalists fail to agree on a common standard for judging what constitutes support for one or another approach.
In recent years, however, an increasing number of constructivist theorists have embraced positivism-the notion that constructivist hypotheses can, and should, be tested and validated or falsified empirically-and these scholars have produced a spate of constructivist work that attempts rigorously to test hypotheses about socialization, norm-diffusion, and collective preference formation in the EU (Wendt 1999; Checkel 2003; Risse 2004: 160). Some of these studies, including Liesbet Hooghe’s (2002, 2005) extensive analysis of the attitudes of Commission officials, and several studies of national officials participating in EU committees (Beyers and Dierickx 1998; Egeberg 1999), use quantitative methods to test hypotheses about the nature and determinants of officials’ attitudes, including socialization in national as well as European institutions. Such studies, undertaken with methodological rigour and with a frank reporting of findings, seem to demonstrate that that EU-level socialization, although not excluded, plays a relatively small role by comparison with national-level socialization, or that EU socialization interacts with other factors in complex ways.