The basic case of reference is the relation between a name and the person or object which it names. The philosophical pro-blems include trying to elucidate that relation, to understand whether other semantic relations, such as that between a predicate and the property it expresses, or that between a description and what it describes, or that between myself and the word ‘I’, are examples of the same relation or of very different ones. A great deal of modern work on this was stimulated by Kripke's Naming and Necessity (1970). It would also be desirable to know whether we can refer to such things as abstract objects and how to conduct the debate about such an issue. A popular approach, following Frege, is to argue that the fundamental unit of analysis should be the whole sentence. The reference of a term becomes a derivative notion: it is whatever it is that defines the term's contribution to the truth condition of the whole sentence. There need be nothing further to say about it, given that we have a way of understanding the attribution of meanings or truth-conditions to sentences. Other approaches search for a more substantive, possibly causal or psychologically or socially constituted, relationship between words and things. See also definite descriptions, denotation, logically proper name.