A familiar assumption in much linguistic semantics is that meanings are to be identified conceptually as, or as subparts of, the conceptual representations deployed in general cognitive processes. However, this assumption has increasingly come into question as a result of developments in the study of cognition both within and outside linguistics. This article reassesses the place of concept-based explanation in semantics in light of these developments, concentrating on the explanatory about the mental architecture supporting meaning. It concludes that while concept-based explanations of meaning are viable for a certain class of referents, their role in a cognitively natural account of the lexicon is subject to significant but little appreciated limitations.