The purpose of this thesis is to demonstrate that metaphysics is a necessary discipline -- necessary in the sense that all areas of philosophy, all areas of science, and in fact any type of rational activity at all would be impossible without a metaphysical background or metaphysical presuppositions. Because of the extremely strong nature of this claim, it is not possible to put forward a very simple argument, although I will attempt to construct one. A crucial issue here is what (...) metaphysics in fact is -- the nature of metaphysics. The conception of metaphysics which I support could be called Aristotelian, as opposed to Kantian: metaphysics is the first philosophy and the basis of all other philosophical and scientific inquiry. I will argue that this is indeed the most plausible conception of metaphysics. (shrink)

This paper argues that a theory of situated vision, suited for the dual purposes of object recognition and the control of action, will have to provide something more than a system that constructs a conceptual representation from visual stimuli: it will also need to provide a special kind of direct (preconceptual, unmediated) connection between elements of a visual representation and certain elements in the world. Like natural language demonstratives (such as `this' or `that') this direct connection allows entities to be (...) referred to without being categorized or conceptualized. Several reasons are given for why we need such a preconcep- tual mechanism which individuates and keeps track of several individual objects in the world. One is that early vision must pick out and compute the relation among several individual objects while ignoring their properties. Another is that incrementally computing and updating representations of a dynamic scene requires keeping track of token individuals despite changes in their properties or locations. It is then noted that a mechanism meeting these requirements has already been proposed in order to account for a number of disparate empiri- cal phenomena, including subitizing, search-subset selection and multiple object tracking (Pylyshyn et al., Canadian Journal of Experimental Psychology 48(2) (1994) 260). This mechanism, called a visual index or FINST, is brie. (shrink)

Taking ontological realism about social groups as the thesis that groups are composite material objects constituted by their members, this paper considers a challenge to the very possibility that groups be regarded as material entities. Ordinarily we believe that two groups can have synchronic co-extensive memberships—for example, the choir and the rugby team—while preserving their distinctive identity conditions. We also doubt that two objects of the same kind can be in the same place at the same time, which would appear (...) to be the case when groups have identical memberships. I explain that the principle denying the synchronic co-location of objects of the same kind need not apply universally to material objects and that it is a mistake to take resistance to penetrability as a necessary feature of materiality. Therefore, initial appearances notwithstanding, groups can be in the same place at the same time. Key Words: identity • materiality • location • social group. (shrink)

The ancient puzzle of Dion and Theon has given rise to a surprising array of apparently implausible views. For example, in order to solve the puzzle, several philosophers have been led to deny the existence of their own feet, others have denied that objects can gain and lose parts, and large numbers of philosophers have embraced the thesis that distinct objects can occupy the same space, having all their material parts in common. In this paper, I argue for an alternative (...) approach: I claim that human beings have ordinary parts—hands, heads, feet, and so on—but no extraordinary parts, such as ‘foot-complements’, the existence of which is essential to the puzzle. I rebut three objections to this approach: an objection that it is unacceptably metaphysically arbitrary, an objection that the view is incompatible with versions of the puzzle involving decapitation, and an objection concerning masses of matter. If we can believe that there are such things as hands and feet without involving ourselves in paradox, and without accepting large numbers of co-located material objects that share all their material parts, then that is what we should do. My view is the only known alternative which allows this. (shrink)

We are confident of many of the judgements we make as to what sorts of alterations the members of nature's kinds can survive, and what sorts of events mark the ends of their existences. But is our confidence based on empirical observation of nature's kinds and their members? Conventionalists deny that we can learn empirically which properties are essential to the members of nature's kinds. Judgements of sameness in kind between members, and of numerical sameness of a member across time, (...) merely project our conventions of individuation. Our confidence is warranted because apart from those conventions there are no phenomena of kind-sameness or of numerical sameness across time. There is just 'stuff' displaying properties. This paper argues that conventionalists can assign no properties to the 'stuff' beyond immediate phenomenal properties. Consequently they cannot explain how each of us comes to be able to wield 'our conventions'. (shrink)

A material object is constituted by a sum of parts all of which are essential to the sum but some of which seem inessential to the object itself. Such object/sum of parts pairs include my body/its torso and appendages and my desk/its top, drawers, and legs. In these instances, we are dealing with objects and their components. But, fundamentally, we may also speak, as Locke does, of an object and its constitutive matter—a “mass of particles”—or even of that aggregate and (...) the sum of subatomic particles ‘making it up’. The “problem of material constitution” (henceforth, PMC) is generated by assuming inter alia that the members of any such pair are numerically identical, that is, that the constituted and the constituting are one and the same thing. (shrink)