Karl Popper launched a specific version of methodological individualism (MI) after World War II. This new version has been very influent, especially via one of Popper’s main followers, John Watkins, probably because Watkins used a much more strictly analytical style in philosophy than his mentor. This Popper-Watkins tradition is nowadays renewed in a rather paradoxical way; while Watkins supported a defense of MI paired with a criticism of holism, the “post-watkinsian” analytical philosophers, on the contrary, strongly criticize MI. This occurs within the context of the parallel emergence of refined versions of holism. These philosophers reconstruct theses and arguments painstakingly but do not take actual debates among the social scientists into account very much. Although, at first sight, the outcome of these artificial reconstructions may seem rather sterile, one can take advantage of them if one investigates whether typical misunderstandings widespread within this tradition might not have sprung from equivocations remaining in the works of the leaders of MI themselves. The definition of MI formulated in 1909 by Joseph A. Schumpeter, who coined the label in order to characterize Carl Menger’s (then Max Weber’s) method, a definition that is still followed in sociology, is taken as a cornerstone.