  Others, however, deny this. For Wiggins, the problem with the claim that all need claims are elliptical is that it blurs the distinction between the instrumental sense of ‘need’, where the purpose for which the claimed item is needed might be almost anything, and the categorical sense where ‘the purpose is already fixed, and fixed by virtue of the meaning of the word’ (Wiggins 1998, 9). In the case of categorical needs, needed items are things that human beings must have to avoid being harmed, but it is a mistake to see ‘avoidance of harm’ as a further end that explains why the need is a need; instead it is already present in the idea of need itself. A similar argument is made by Thomson (1987), though using a different vocabulary of derivative and basic needs. Of course these analyses of the concept of need do not yet tell us what our categorical or basic needs are. It is uncontroversial to say that the resources without which a human being could not survive, such as food and water, count as needs. But how far beyond this does the concept stretch? Could needs that only some people have count as categorical, for example? We return to this question in section 3 below when we discuss different substantive theories of need.