I examine an argument that has recently appeared in the cognitive science literature in favor of thinking that the mind is mostly composed of Fodorian-type cognitive modules; an argument that concludes that a mind that is massively composed of classical cognitive mechanisms that are cognitively modular is more evolvable than a mind that is not cognitively modular, since a cognitive mechanism that is cognitively modular is likely to be biologically modular, and biologically modular characters are more evolvable. I argue that (...) the notion of cognitive modularity needed to make this argument plausible will have to be understood in terms of the biological notion of variational independence, as follows: a cognitive feature is cognitively modular only if few or no other morphological changes are significantly correlated with variations of that feature arising in members of the relevant population as a result of ontogeny. I also argue that most of the connotations contained in a cluster of notions of classical cognitive modularity are, as far as we know, irrelevant to the argument, and that only the presence of selective impairments—also known as cognitive dissociations—can be considered as strong indicators of the type of modularity that genuinely enhances evolvability. (shrink)