Dispositions

Appeals to dispositionality in explanations of phenomena in metaphysics and the philosophy of mind, require that we first agree on what we are talking about. I sketch an account of what dispositionality might be. That account will place me at odds with most current conceptions of dispositionality. My aim is not to establish a weighty ontological thesis, however, but to move the discussion ahead in two respects. First, I want to call attention to the extent to which assumptions philosophers have made about dispositionality are far from innocent. The assumptions incorporate substantive theses that, by constraining the space of ‘acceptable’ answers to particular philosophical questions, have inhibited the search for answers to those questions. Second, and more positively, I hope to open up the space of possibilities by offering an alternative way of conceiving dispositionality developed by C. B. Martin. 1. WHAT is A DISPOSITION? ‘Disposition’ is a term of art: you can define dispositions as you please. Some conceptions of dispositionality, however, are more felicitous than others. As I use the term, a disposition is a power or capacity. Locke makes powers the cornerstone of his ontology. A signet has the power – is disposed to – imprint wax in a particular way; wax has the reciprocal power – is reciprocally disposed – to be so imprinted by signets of that kind. I shall say more about Locke presently. For the moment I want only to note that many philosophers – from Boscovich and Priestley in the 18th century, to Harré and Madden, Sydney Shoemaker, and Nancy Cartwright more recently – have been attracted to the idea that our world is a world of ‘powerful particulars’.1 Before we can make use of dispositionality to explain assorted phenomena in the philosophy of mind and elsewhere, we need to agree on ∗This paper was written for a conference on Dispositions and Laws of Nature held at the University of Alabama, Birmingham, 7–8 February 2003; Michael Watkins commented. I have benefited from those comments, from remarks by other participants, and from discussions with David Armstrong and my colleague, David Robb, on the topic. The account sketched here is based on C. B. Martin’s work on dispositions. See Martin (1992, 1993, 1994, 1997), Martin and Heil (1999), and Martin’s contribution to Armstrong et al. (1996). The position is developed in detail in Heil (2003). Synthese (2005) 144: 343–356 © Springer 2005