The term ‘agentive’ is a familiar one in current discussions of the syntax of English (and other languages). Although most who use it seem, at first glance, to be referring to more or less the same semantic feature, the term is employed in a variety of ways. For instance, Fillmore (1968: 24) talks of an ‘agentive case’; Gruber (1967: 943) has ‘agentive verbs’; Lyons and others speak of ‘agentive nouns’; while Halliday (1967: 196), although he does not use the term ‘agentive’, distinguishes a feature of clauses which is clearly related to the notion of agentivity. Apart from this disagreement as to what, precisely, the term ‘agentive’ is to be predicated of, there is a further divergence of opinion over which nouns (or verbs, etc.) are to be considered agentive. For instance, Lyons marks the surface subject of see as agentive (1968: 387). Fillmore, on the other hand, assigns this to the dative case, and Gruber classifies see as a non-agentive verb. Again, Lyons and Halliday take up what are in effect incompatible positions with regard to the status of the prisoners in John marched the prisoners. In view of this indeterminacy, it seems worthwhile to attempt a critical examination of the notion of agentivity, in the hope that a clearer characterization of it might emerge.