Spencer's heritage, while almost a forgotten chapter in the history of biology, lives on in psychology and the philosophy of mind. I particularly discuss externalist views of meaning, on which meaning crucially depends on a notion of reference, and ask whether reference should be thought of as cause or effect. Is the meaning of a word explained by what it refers to, or should we say that what we use a word to refer to is explained by what concept it expresses? I argue for the latter view, which I call 'Darwinian', and against the former, 'Spencerian' one, assuming conceptual structures in humans to be an instance of adaptive structures, and adaptive relations to an environment to be the effect rather than the cause of evolutionary novelties. I conclude with the deficiency - both empirically and methodologically - of a functionalist study of human concepts and the languages they are embedded in, as it would be undertaken in a paradigm that identifies meaning with reference or that gives reference an explanatory role to play for what concepts we have.PUBLICATION ABSTRACT