This paper takes as its starting point the observation of quasi-religious, ‘cultural’ characteristics in the dominant discourse of Western liberal democracy, and of ‘ideological’ characteristics in the discourse of Islamism – noting that both discourses rely, to some extent, upon the notion of rationality. Having provided working definitions of rationality, ideology, and culture, it goes on to argue that culture and ideology may be viewed as discursive macro-strategies which are related to the degree of power enjoyed by a given social (...) system at particular historical moments in time: the former being associated with the consolidation of established power and the latter with a bid to acquire power. It suggests that the general function of cultural and ideological strategies is to mask the underlying irrationalities of free-market democracy and Islamism, respectively, and concludes by considering some of the implications of this view in the context of globalization and the ‘war on terror’. (shrink)