Amie Thomasson has won well-deserved praise for her book, Ordinary Objects. She defends a commonsense world view and gives us “reason to think that there are fundamental particles, plants and animals, sticks and stones, tables and chairs, and even marriages and mortgages.” (p. 181) Ordinary objects comprise a vast array of things—natural objects both scientific and commonsensical, artifacts, organisms, abstract social objects.

Metaphysics has enjoyed a vigorous revival in the last few decades. Even so, there has been little ontological interest in the things that we interact with everyday—trees, tables, other people.1 It is not that metaphysicians ignore ordinary things altogether. Indeed, they are happy to say that sentences like ‘The daffodils are out early this year’ or ‘My computer crashed again’ are true. But they take the truth of such sentences not to require that a full description of reality mention daffodils (...) or computers. Many metaphysicians now interpret the apparent variety of things in the world as variety only of concepts applied to things that are basically of the same sort—for example, sums of particles or of temporal parts of particles. (shrink)

In defense of de re necessity, Saul Kripke proposes that a material object could not have originated in a substance different in kind from the substance in which it actually originated. I give a counterexample to this proposal.

Is the self a substance, as Descartes thought, or is it 'only' a bundle of perceptions, as Hume thought ? In this paper I will examine these two views, especially with respect to two central features that have played a central role in the discussion, both of which can be quickly and usefully explained if one puts them as an objection to the bundle view. First, friends of the substance view have insisted that only if one conceives of the self (...) as a substance is it possible to account for genuine particularity of selves and genuine persistence through time of them. I will discuss in detail this claim as well as a special case of persistence - the case of a fission of a self - and I will ask, as Shoemaker (1997) did, how such a case can be handled by the two competing theories. The second central point of traditional disagreement concerns independence : it is often said that only a substance, but not a mere bundle, is independent enough of its properties to play properly the role of a self, and I will have something to say about this. Concerning all these points, my thesis will be a meta-theoretical one : contrary to appearances, both views can accommodate all of them (particularity at a time, persistence, fission, independence) in the same way, and I will examine two possible conclusions to be drawn from this : either that the differences between the two views are no more than terminological and that they turn out to be equivalent views, or that the differences are metaphysical but that it is epistemically under-determined which one of the views we should choose. (shrink)

Two fundamental categories of any ontology are the category of objects and the category of universals. We discuss the question whether either of these categories can be infinite or not. In the category of objects, the subcategory of physical objects is examined within the context of different cosmological theories regarding the different kinds of fundamental objects in the universe. Abstract objects are discussed in terms of sets and the intensional objects of conceptual realism. The category of universals is discussed in (...) terms of the three major theories of universals: nominalism, realism, and conceptualism. The finitude of mind pertains only to conceptualism. We consider the question of whether or not this finitude precludes impredicative concept formation. An explication of potential infinity, especially as applied to concepts and expressions, is given. We also briefly discuss a logic of plural objects, or groups of single objects (individuals), which is based on Bertrand Russell’s (1903, The principles of mathematics, 2nd edn. (1938). Norton & Co, NY) notion of a class as many. The universal class as many does not exist in this logic if there are two or more single objects; but the issue is undecided if there is just one individual. We note that adding plural objects (groups) to an ontology with a countable infinity of individuals (single objects) does not generate an uncountable infinity of classes as many. (shrink)

In his paper [2], Hud Hudson presents an interesting argument to the conclusion that two temporally–continuous, spatially–unextended material objects can travel together for all but the last moment of their existences and yet end up one metre apart. What is surprising about this is that Hudson argues that it can be achieved without either object changing in size or moving discontinuously. This would be quite a trick were it to work, but it is far from clear that it does. The (...) problem is that Hudson’s implicit notion of continuity is not the standard one. On the standardly–accepted definition of continuity, his example is straightforwardly a case of discontinuous motion. And there is no surprise that Hudson’s trick can be achieved by invoking discontinuous.. (shrink)

This book is a complete re-thinking of Aristotle's metaphysical theory of material substances. The view of the author is that the 'substances' are the living things, the organisms: chiefly, the animals. There are three main parts to the book: Part I, a treatment of the concepts of substance and nonsubstance in Aristotle's Categories; Part III, which discusses some important features of biological objects as Aristotelian substances, as analysed in Aristotle's biological treatises and the de Anima; and Part V, which attempts (...) to relate the conception of substance as interpreted so far to that of the Metaphysics itself. The main aim of the study is to recreate in modern imagination a vivid, intuitive understanding of Aristotle's concept of material substance: a certain distinctive concept of what an individual material object is. (shrink)

On a widely shared assumption, our mental states supervene on our microphysical properties – that is, microphysical supervenience is true. When this thesis is combined with the apparent truism that human persons have proper parts, a grave difficulty arises: what prevents some of these proper parts from being themselves thinkers as well? How can I know that I am a human person and not a smaller thinker enclosed in a human person? Most solutions to this puzzle make radical, if not (...) absurd, claims. Recently, however, Michael Burke and Howard Robinson proposed conservative solutions that, according to them, do not have such undesired consequences. This paper argues that the conservative solutions tacitly assume at least one of the radical ones, and therefore they provide no alternative to the extreme solutions. (shrink)

Physical objects are the most familiar of all objects, and yet the concept of a physical object remains elusive. Any six-year-old can give you a dozen examples of physical objects, and most people with at least one undergraduate course in philosophy can also give examples of non-physical objects. But if asked to produce a definition of ‘physical object’ that adequately captures the distinction between the physical and the nonphysical, the average person can offer little more than hand-waving.

The concept of a physical object has figured prominently in the history of philosophy, and is probably more important now than it has ever been before. Yet the question What are physical objects?, i.e., What is the correct analysis of the concept of a physical object?, has received surprisingly little attention. The purpose of this paper is to address this question. I consider several attempts at answering the question, and give my reasons for preferring one of them over its rivals. (...) The account of physical objects that I recommend – the Spatial Location Account – defines physical objects as objects with spatial locations. The intuitive idea behind the Spatial Location Account is this. Objects from all of the different ontological categories – physical objects; non-physical objects like souls, if there are any; propositions; universals; etc. – have this much in common: they all exist in time. But not all of them exist in space. The ones that exist in time and space, i.e., the ones that have spatial locations, are the ones that count as physical objects. (shrink)

It is argued that according to Aristotle the universe is a single substance with its own form and matter.

Suppose that a material object is gunky: all of its parts are located in space, and each of its parts has a proper part. Does it follow from this hypothesis that the space in which that object resides must itself be gunky? I argue that it does not. There is room for gunky objects in a space that decomposes without remainder into mereological simples.

This paper offers a critical assessment of the current state of the debate about the identity and individuality of material objects. Its main aim, in particular, is to show that, in a sense to be carefully specified, the opposition between the Leibnizian ‘reductionist’ tradition based on discernibility and the sort of ‘primitivism’ that denies that facts of identity and individuality must be analysable has become outdated. In particular, it is argued that – contrary to a widespread consensus - ‘naturalised’ metaphysics (...) supports both the acceptability of non-qualitatively grounded (both ‘contextual’ and intrinsic) identity and a pluralistic approach to individuality and individuation. A case study is offered that focuses on non-relativistic quantum mechanics, in the context of which primitivism about identity and individuality, rather than being regarded as unscientific, is on the contrary suggested to be preferable to the complicated forms of reductionism that have recently been proposed. More generally, assuming a plausible form of anti-reductionism about scientific theories and domains, it is claimed that science can be regarded as compatible with, or even as suggesting, the existence of a series of equally plausible grades of individuality - the kind of individuality that prevails in a certain context and at a given level being ascertainable only on the basis of the specific scientific theory at hand. (shrink)

Function theorists routinely speculate that a viable function theory will be equally applicable to biological traits and artifacts. However, artifact function has received only the most cursory scrutiny in its own right. Closer scrutiny reveals that only a pluralist theory comprising two distinct notions of function--proper function and system function--will serve as an adequate general theory. The first section describes these two notions of function. The second section shows why both notions are necessary, by showing that attempts to do away (...) with one of them fail. This demonstration draws on examples from the artifactual realm to motivate major points of the argument. The third section is an outline of artifact function. It confirms the conclusions of the second section, and also begins the task of describing some of the special features of artifact function needing accommodation within the general theory. (shrink)

There is a tradition according to which Parmenides of Elea endorsed the following set of counterintuitive doctrines: (a) There exists exactly one material thing. (b) What exists does not change. (g) Nothing is generated or destroyed. (d) What exists is undivided. For convenience, I will use the label ‘Eleatic monism’ to refer to the conjunction of a–d.

Philosophical naturalism, according to which philosophy is continuous with the natural sciences, has dominated the Western academy for well over a century, but Michael Rea claims that it is without rational foundation. Rea argues compellingly to the surprising conclusion that naturalists are committed to rejecting realism about material objects, materialism, and perhaps realism about other minds.

Can our ordinary conception of macroscopic objects be transposed to the framework of relativity theory? According to common sense, ordinary objects cannot undergo radical variation in shape, whereas according to a compelling and widely accepted metaphysical picture of ordinary objects’ shapes in Minkowski spacetime, they do undergo such radical variation. This problem raises doubts about the compatibility of the ordinary conception and the relativistic conception of the world. I shall propose to reconcile common sense with relativistic metaphysics by viewing ordinary (...) objects as doublelayered compounds of matter and form. The different layers permit different perspectives on the objects, the one perspective focusing on form and the other focusing on matter. This ontology allows the conception of common sense and the conception of relativistic metaphysics to manifest different and compatible perspectives on the same objects. (shrink)

What happens to a person in a case of fission? Does it survive? Does it go out of existence? Or is the outcome indeterminate? Since each description of fission based on the persistence conditions associated with our ordinary concept of a person seems to clash with one or more platitudes of common sense about the spatiotemporal profile of macroscopic objects, fission threatens the common-sense conception of persons with inconsistency. Standard responses to this paradox agree that the common-sense conception of persons (...) is unstable, differing over which part of the conception requires revision. I will show that this entrenched view of fission is not compulsory. I will develop a solution to the paradox that maintains the consistency of the common-sense conception of persons on the basis of an ontology of persons and other ordinary objects as double-layered compounds. Each of various descriptions of the outcome of personal fission is compatible with principles about the spatiotemporal profile of persons, because the descriptions and the principles manifest different perspectives on persons and are made true or false by different ontological components of the latter. What holds for the fission of persons, holds for the fission of other kinds of objects. (shrink)

I argue that from a very weak recombination principle and plausible assumptions about the nature of parthood and location it follows that it's possible that the mereological structure of the material world and that of spacetime fail to correspond to one another in very radical ways. I defend, moreover, that rejecting the possibility of such failures of correspondence leaves us with a choice of equally radical alternatives. I also discuss a few ways in which their possibility is relevant to various (...) debates in metaphysics. (shrink)

A not-unpopular position in the metaphysics of material objects (Ted Sider's, for instance) combines realism about what objects there are and the conditions of objecthood with conventionalism about de re modality. I argue that this is not a coherent combination of views: one must go fully conventionalist, or fully realist. The central argument displays the difficulty for the modal conventionalist/object realist in specifying the object that satisfies de re modal predicates. I argue that if this is a mind-independent object, contradictions (...) arise when we consider the possibility or actuality of non-equivalent conventions both applying to 'the same object'. (shrink)

to appear in A. Coliva (ed.), Manuale di filosofia analitica, Roma: Carocci.

Holes are an interesting case-study for ontologists and epistemologists. Naive, untutored descriptions of the world treat holes as objects of reference, on a par with ordinary material objects. (‘There are as many holes in the cheese as there are cookies in the tin.’) And we often appeal to holes to account for causal interactions, or to explain the occurrence of certain events. (‘The water ran out because of the hole in the bucket.’) Hence there is..

An essential property is a property that an object possesses in every possible world in which that object exists. An individual essence is a property (or set of properties) that an object possesses in every world in which that object exists, and that no other object possesses in any possible world. Call the claim that some artifacts possess an individual essence ‘artifactual essentialism’. I will argue that artifactual essentialism is true.