Abstract“Science Is Politics By Other Means” (SIPBOM) was coined in The Pasteurization of France, Latour’s 1984 empirical study of the birth of microbiology. Yet, it encapsulates an outstanding political theory of science that Latour has never formalized and that has remained unnoticed to this day. The theory is comprised of two dimensions. The first one is the ontological labor performed by science, that is, the laboratory production of new nonhumans. The second one is the ability of science to devise and (...) implement novel policies targeted at the new beings it produces. These “other means” are incorporated in political projects and contribute to the shaping of society. Fifteen years later, Latour published Politics of Nature ([1999] 2004), a full-blown political treatise equally devoted to the political character of science. It would be mistaken, however, to assume that it falls in the same SIPBOM paradigm as the Pasteur study. The compositionist theory it offers redefines politics as the institution of the nonhumans that make up external reality, a task that has traditionally been monopolized by Science. In this sense, “science is politics by other means” has become “politics is science by other means,” these “other means” now referring to “cosmopolitics,” that is, the due process advocated by compositionism. The first claim of the present paper is that the respective weight ascribed to politics and ontology is different in The Pasteurization of France and in Politics of Nature. The second claim is that compositionism is not as successful as Latour’s early theory to account for the politicity of science. (shrink)