Abstract

Available from UMI in association with The British Library. ;A form of metaphysical inquiry is in this thesis both illustrated in detail and defended against the charge of issuing in statements which lack cognitive content. 'Categorial description' concerns the fundamental features of our conceptual scheme: the categories described are those of substance, accident, cause, space and time. ;Following Aristotle's distinction between primary and secondary substances, these two notions are addressed as equivalent to those individual or particular things and their kinds. A particular thing is characterised as not being capable of occuring in the predicate position in a proposition; and as having criteria or principles of individuation and reidentification. Accidents or properties can appear in the predicate position and do not have criteria of identity. ;Secondary substances, or natural kinds, being a species of property, also fail to have criteria for individuation and reidentification. It follows that the recently revived Aristotelian essentialism, as exhibited in particular in the work of Kripke, fails to correctly characterise the category of natural kinds: in that theory, natural kinds have essential properties which enable individuation and reidentification across possible worlds. ;Efficient causation is described, against the background of the Locke-Hume dispute, as involving the concept of necessary connection between cause and effect. Rejecting the theory of Harre and Madden on causal powers, an approach by Mackie is defended whereby this connection is a reflection of our counterfactual thinking. The possible worlds essentialist approach of Lewis to counterfactuals is rejected too, as inadequate. ;Space and time, spatial and temporal relations, and places and moments in time are approached in terms of the other categories of particular and property. The obscurity of fit between these categories is identified as responsible for many philosophical puzzles concerning space and time: for example, McTaggart's 'proof' of the unreality of time; and the recent debate on the possibility of multiple times and multiple spaces. ;In the final chapter, the logical commitments of categorial description concerning conceptual relativism and the nature of reality in itself are explored. It is argued that, since categories are in large part responsible for the kinds of acts there are, a description of our categories is a description of reality itself. Since our categories do not involve the machinery of possible worlds offered by contemporary essentialist theories, those theories fail to describe reality