Abstract
Philosophers of mind (from eliminative materialists to psychofunctionalists to interpretivists) generally assume that a normative ideal delimits which mental phenomena exist (though they disagree about how to characterize the ideal in question). This assumption is dubious. A comprehensive ontology of mind includes some mental phenomena that are neither (a) explanatorily fecund posits in any branch of cognitive science that aims to unveil the mechanistic structure of cognitive systems nor (b) ideal (nor even progressively closer to ideal) posits in any given folk psychological practice. Indeed, one major function of scientific psychology has been (and will be) to introduce just such (normatively suboptimal but real) mental phenomena into folk psychological taxonomies. The development and public dissemination of IQ research over the course of the 20th century is a case in point.