It specifies the differences between such historicism and what he calls respectively ‘selective’ and ‘reductive’ versions of historicism. These versions are inadequate conceptualisations of the ‘sheer flow of time’ that, on Rockhill’s view, defines history. He likens this sheer flow of time to a ‘universal acid’ that dissolves the supposed stability of cherished categories (37). Selective history ‘postulates the existence of a fixed kernel behind historical change’ (36). It is selective because it exempts this kernel from change. The reductive version ties historical development to specifiable historical determinants (36). According to Rockhill, ‘all of our practices . . . are fundamentally historical, but . . . this does not mean that they are somehow reducible to a unique set of historical determinants’ (36-37). In contrast to such a view, he explains his radical historicism with reference to Foucault’s preference for an ‘analytic’ of how power operates rather than a ‘theory’ of what power is (37): the idea, transposed to Rockhill’s project, is that there is no art or politics in general but ‘immanent practices that are qualified as “artistic” or “political” in variable sociohistorical conjunctures’ (37).