<b>The Symmetrical Leviathan </b><b></b>

Steven Shapin and Simon Schaffer’s main contribution has been to show how science can be understood as a complex activity. This perspective encourages a view of scientific endeavour not only in terms of its outcomes, but as a more holistic process that includes experiments, instruments, and discourses. From this perspective, the principle of symmetry established by the Sociology of Scientific Knowledge (SSK) programme plays a central role. In this paper we would like to analyse three aspects of the historical research carried out by the SSK authors: first, the tensions between historical and sociometric modes of inquiry; second, the emergence of the symmetry principle as a founding criterion of the SSK programme and its implication in the internal/external debate; and finally, a critical suggestion about the type and self of the historian who conducts the history of science on the basis of the SSK.