Origins of the EU 51 cross-cutting groups of people in similar material positions.This does not mean that ideas have stronger causal effects where they cross-cut groups;ideas shared within powerful groups may be equally (or more)significant for important outcomes.It simply means that ideas'autonomous effects should be particularly demonstrable in these cases. To see this assertion in greater detail,consider how it responds to the"how much" problem.We could isolate ideas precisely if we found an extremely close compar- ison,contrasting actors in near-identical places in the objective world to highlight the purely subjective variations in their behavior.Such comparisons are available at the individual level,within groups.Close organizational peers share positions in the objective world;comparing their views of their groups'interests can separate variation in their ideas from variation in objective pressures.Take two French diplomats,with similar social backgrounds and party sympathies,in the same office of the foreign ministry in 1950.One insists on French interests in a new "suprana- tional"Franco-German federation;the other sees French interests in policies based on an informal partnership with Britain.These similarly placed individuals face all the same objective pressures but seem to interpret them differently.If other similarly placed individuals across France also disagree (displaying a pattern that cross-cuts parties,bureaucracies,economic groups),and if these debates persist through important decisions (showing they were not just an initial vetting of options),we can conclude that objective pressures at these levels leave French interests indeterminate across these alternatives.If,in addition,we have the kind of"interpretive"evidence typically offered by ideational accounts-actors consistently say and write that they believe certain things,and that their peers think differently-we have strong evidence that ideas alone are causing individual variation across that range.7 This conclusion does not rule out that historical or psychological factors other than simple"ideas"(like past socialization,psychological dispositions,or individual experiences)may have led to this pattern of debate.But as long as we cannot trace current patterns of mobilization to current objective conditions (and can trace related patterns of rhetoric),we have evidence that subjective factors are currently influencing action.Psychological or historical factors may help explain why actors came to hold certain ideas,but neither factor invalidates the claim that subjective ideas are now causing variation in behavior.In other words,explaining the distribution of ideas as dependent variables is legitimately separate from showing their presence and effects as independent variables.s Far from exaggerating the range of purely subjective variation in individuals' views,this approach should minimize interpretive biases.Unlike in most ideational arguments,it is the actors,not the observer,who define the range across which ideas matter (see Figure 1).One actor wants to pursue strategy X;one of her close 17.Provided there are no clear individual-level incentives to disagree,as in career competition.I see no pattern of such incentives in my case.Disincentives to interal disagreement seem more common in most organizations. 18.See Kingdon 1984.77:Kier 1997.148:and Kowert and Legro 1996.469.cross-cutting groups of people in similar material positions. This does not mean that ideas have stronger causal effects where they cross-cut groups; ideas shared within powerful groups may be equally (or more) significant for important outcomes. It simply means that ideas’ autonomous effects should be particularly demonstrable in these cases. To see this assertion in greater detail, consider how it responds to the “how much” problem. We could isolate ideas precisely if we found an extremely close compar￾ison, contrasting actors in near-identical places in the objective world to highlight the purely subjective variations in their behavior. Such comparisons are available at the individual level, within groups. Close organizational peers share positions in the objective world; comparing their views of their groups’ interests can separate variation in their ideas from variation in objective pressures. Take two French diplomats, with similar social backgrounds and party sympathies, in the same office of the foreign ministry in 1950. One insists on French interests in a new “suprana￾tional” Franco-German federation; the other sees French interests in policies based on an informal partnership with Britain. These similarly placed individuals face all the same objective pressures but seem to interpret them differently. If other similarly placed individuals across France also disagree (displaying a pattern that cross-cuts parties, bureaucracies, economic groups), and if these debates persist through important decisions (showing they were not just an initial vetting of options), we can conclude that objective pressures at these levels leave French interests indeterminate across these alternatives. If, in addition, we have the kind of “interpretive” evidence typically offered by ideational accounts—actors consistently say and write that they believe certain things, and that their peers think differently—we have strong evidence that ideas alone are causing individual variation across that range.17 This conclusion does not rule out that historical or psychological factors other than simple “ideas” (like past socialization, psychological dispositions, or individual experiences) may have led to this pattern of debate. But as long as we cannot trace current patterns of mobilization to current objective conditions (and can trace related patterns of rhetoric), we have evidence that subjective factors are currently influencing action. Psychological or historical factors may help explain why actors came to hold certain ideas, but neither factor invalidates the claim that subjective ideas are now causing variation in behavior. In other words, explaining the distribution of ideas as dependent variables is legitimately separate from showing their presence and effects as independent variables.18 Far from exaggerating the range of purely subjective variation in individuals’ views, this approach should minimize interpretive biases. Unlike in most ideational arguments, it is the actors, not the observer, who define the range across which ideas matter (see Figure 1). One actor wants to pursue strategy X; one of her close 17. Provided there are no clear individual-level incentives to disagree, as in career competition. I see no pattern of such incentives in my case. Disincentives to internal disagreement seem more common in most organizations. 18. See Kingdon 1984, 77; Kier 1997, 148; and Kowert and Legro 1996, 469. Origins of the EU 51