   Elster does not draw as sharp a distinction as he might have between the commitment to methodological individualism and the commitment to rational choice theory. Indeed, he also assumes that the latter flows directly from the former. The version of rational choice theory that Elster endorses, however, is one that is based upon a traditional instrumental (or homo economicus) conception of rationality, according to which “actions are valued and chosen not for themselves, but as more or less efficient means to the a further end” (Elster 1989, 22). He claims that this conception of rationality is implied by the fact that decision theorists are able to represent the rational actions of any agent possessing a well-behaved preference ordering as the maximization of a utility function. Yet whether utility-maximization implies instrumentalism depends upon the version of expected utility theory that one subscribes to. So-called “world Bayesian” versions of decision theory, such as Richard Jeffrey’s (1983) do not impose an instrumental conception of rationality, since they permit agents to have preferences over their own actions. Thus Elster’s move from methodological individualism to the instrumental conception of rationality is based upon a non sequitur.