 For all that signification is posterior to reference, names do have signification as well. Abelard holds that the signification of a term is the informational content of the concept that is associated with the term upon hearing it, in the normal course of events. Since names are only conventionally significant, which concept is associated with a given name depends in part on the psychological conditioning of language-users, in virtue of which Abelard can treat signification as both a causal and a normative notion: the word ‘rabbit’ ought to cause native speakers of English to have the concept of a rabbit upon hearing it. Abelard is careful to insist that the signification is a matter of the informational content carried in the concept—mere psychological associations, even the mental images characteristic of a given concept, are not part of what the word means. Ideally, the concept will correspond to a real definition that latches onto the nature of the thing, the way ‘rational mortal animal’ is thought to be the real definition of ‘human being’, regardless of other associated features (even necessary features such as risibility) or fortuitous images (as any mental image of a human will be of someone with determinate features). Achieving such clarity in our concepts is, of course, an arduous business, and requires an understanding of how understanding itself works (see the discussion of Abelard’s philosophy of mind in  Section 5).  Yet one point should be clear from the example. The significations of some names, such as those corresponding to natural-kind terms, are abstractions in the sense that they include only certain features of the things to which the term refers. They do not positively exclude all other features, though, and are capable of further determinate specification: ‘rational mortal animal’ as the content of the concept of ‘human being’ signifies all humans, whatever their further features may be—tall or short, fat or thin, male or female, and so on.