Is the work of Michael Hardt and Antonio Negri compatible with critical realism? In this article I argue that their book Empire is not, whereas Multitude is. Critical realists should be interested in this question because the passage from Empire to Multitude can be reconstructed as a case of critical realist underlabouring and, as such, exemplifies an openness to critique and changing political circumstances that critical realists prescribe for themselves but unfortunately tend in practice to ignore. Highlighting the concepts and (...) practice of underlabouring, of judgemental rationality and epistemological relativism, I argue that Hardt and Negri can also underlabour for critical realists, in that their work demonstrates the need for underlabouring to proceed in a non-philosophical as well as philosophical vein. Thus, striving for a new science and human emancipation in critical realism can assume a theoretically as well as an empirically informed content, and a historically situated commitment. (shrink)