As Peter Hall argues, "unless cultural theories can account for the origins of attitudes by reference to the institutions that generate and reproduce them, they do little more than summon up a deus ex machina that is itself unexplainable." The authors show that standard demographic variables cannot explain intrastate variation in party identification and ideological identification, and then attribute the unexplained variance to political culture. Typical is Brian Barry's argument that a democratic political culture is a learned response to living under democratic institutions rather than, as he claims Gabriel Almond and Sidney Verba argue in their seminal work, The Civic Culture, a prerational commitment exerting a causal force upon those institutions. The significance of Almond and Verba's typology of parochial, subject, and participatory orientations to politics was that it offered a classificatory scheme that enabled scholars to make cross-national comparisons among what had hitherto been seen as totally unique political cultures.