LECTURE CANCELLED!!
ABSTRACT
There is currently intense interest in the question of the source of our presumed knowledge of modal truths — where by ‘modal truths’ I mean, more specifically, truths concerning what is, or is not, metaphysically possible or necessary. Some philosophers try to locate this source in our capacities to conceive or imagine various actual or non-actual states of affairs, but this approach is open to certain familiar and seemingly powerful objections. A different and ostensibly more promising approach has been developed recently by Timothy Williamson, according to which our capacity for modal knowledge is just an extension, or by-product, of our general capacity to acquire knowledge of true counterfactual conditionals — a capacity that we deploy ubiquitously in everyday life. Williamson’s theory crucially involves a thesis to the effect that modal truths can be analysed or defined in terms of counterfactual truths. In this paper, I shall query Williamson’s account on a number of points, including this thesis. I have in fact for a long time defended the very reverse of this thesis, namely, that counterfactual truths are instead to be defined in terms of modal truths. If modal truths are thus prior to counterfactual truths, it seems hopeless to pursue Williamson’s proposal, and we need an alternative one. And we do in any case, I shall argue, since there are defects in Williamson’s proposal which do not turn on the foregoing point. My own positive proposal, which owes an intellectual debt to the work of Kit Fine on modality and essence, appeals instead to our capacity to grasp essences — where essences are understood not in the currently prevailing fashion, made famous by the work of Saul Kripke, according to which all talk of essences may be explicated in terms of the language of ‘possible worlds’, but rather in a neo-Aristotelian fashion, according to which essences are expressed by ‘real definitions’.