REALISM AND REASONABLENESS 1
Some questions in philosophical logic are able to divide philosophers into warring camps. Since the middle of the twentieth century, this has been the case with the question of the status of dispositional statements (and with the closely related question of the status of counterfactual conditionals). For some philosophers dispositions are simply part of 'the furniture of the universe'; for others, the use of a dispositional notion in a philosophical analysis is a sign of 'low standards', of willingness to 'explain the obscure by the still more obscure'; while for still others (perhaps the silent majority) dispositional notions are unavoidable in what we do but troubling to the conscience. This is a relatively new state of affairs: the writers who make up the canon of 'Modern Philosophy' (or at least of seventeenth-century to mid-nineteenth-century philosophy) all availed themselves of the notion of a Power (i.e., a dispositional property) without any visible pangs of conscience.
Perhaps this is not surprising, as it is only since the appearance of mathematical logic that we have realized how hard it is to give an interpretation of counterfactual conditionals and of dispositional predicates in truth- functional 2 terms. But, in a way, it should have been realized a long time ago that the talk of Powers in 'modern' philosophy was problematical, for such talk is a hang-over from medieval philosophy, not something that belongs in its own right to the new picture. The heart of the new picture is the new conception of the 'external' world, the