I find Mr Sumner's typology quite congenial probably because I have Mr Sumner's politics, more or less, and his way of carving up the ideological space places us where we see ourselves: as "pragmatic libertarians" leaning a bit more toward "progressive idealism" than "dogmatic libertarianism". That said, there is something troubling about the lack of parallelism in Mr Sumner's scheme. While conservatism and progressivism both have "idealistic" and "corrupt" variants, libertarianism is only "dogmatic" and "pragmatic". I think the ideological influence but electoral insignificance of libertarianism goes some way toward justifying its different treatment. But I wouldn't want to leave out the possibility of conservatism and progressivism that is pragmatic in the sense of pursuing conservative and progressive values through practical, empirically-tested means, and not in the "corrupt" sense of catering to the electoral interests of a partisan faction.