On some level, we political scientists think we understand some things about thecauses of democratization; we share a conventional wisdom. However, theconventional wisdom is fragmented and not well integrated: it consists of dozensof propositions about the conditions that favor democracy. Although there is acore of propositions that most scholars consider credible, this conventionalwisdom is poorly integrated. Some propositions can be grouped into competingschools of thought but, as we consume, interpret, test, and cite the literature,we tend to consider each proposition in isolation, as though it could stand orfall on its own without affecting our belief in other propositions. What passesfor the conventional wisdom is not, therefore, an integrated theory ofinterwoven propositions; the plural, conventional wisdoms would be moreaccurate. Our collective beliefs about democratization resemble checklists:lists of independent, unconnected items. Checklists are useful for reminding usabout all of the varied factors that may be important. Unfortunately, just as agrocery list is not a short story, a checklist is not a coherent and integratedexplanation.

There is no official screening committee that certifies that a proposition isgenerally true and rigorously supported before it joins one of the conventionalwisdoms. Rather, our conventional wisdoms are just that: matters of convention.Whatever ideas many scholars have found convincing at one time or another cometo be part of what we believe. Because different scholars are convinced bydifferent things, conventional wisdoms are a hodgepodge of ideas originatingfrom diverse sources. To be sure, some propositions have survived repeatedtesting in large samples using the most rigorous techniques in our toolkits. Butmany of them are the conclusions of less rigorous studies that were soconvincing, in their way, that we have incautiously assumed the conclusions tobe generally true. Many comparativists are impressed by intimate knowledge ofthe politics of a particular country or a region, so the conclusions of casestudies and intraregional comparisons sometimes yield insights of a particularlysolid kind, and we sometimes elevate these insights to the status of universaltruth. Some ideas have been treated as received wisdom since the infancy ofcomparative politics, when the field was limited to comparisons of Britain,France, and Germany.