This provocative book attempts to resolve traditional problems of identity over time. It seeks to answer such questions as 'How is it that an object can survive change?' and 'How much change can an object undergo without being destroyed'? To answer these questions Professor Heller presents a theory about the nature of physical objects and about the relationship between our language and the physical world. According to his theory, the only actually existing physical entities are what the author calls 'hunks', (...) four-dimensional objects extending across time and space. This is a major contribution to ontological debate and will be essential reading for all philosophers concerned with metaphysics. (shrink)

In _Real Natures and Familiar Objects_ Crawford Elder defends, with qualifications, the ontology of common sense. He argues that we exist -- that no gloss is necessary for the statement "human beings exist" to show that it is true of the world as it really is -- and that we are surrounded by many of the medium-sized objects in which common sense believes. He argues further that these familiar medium-sized objects not only exist, but have essential properties, which we are (...) often able to determine by observation. The starting point of his argument is that ontology should operate under empirical load -- that is, it should give special weight to the objects and properties that we treat as real in our best predictions and explanations of what happens in the world. Elder calls this presumption "mildly controversial" because it entails that arguments are needed for certain widely assumed positions such as "mereological universalism". Elder begins by defending realism about essentialness. He then defends this view of familiar objects against causal exclusion arguments and worries about vagueness. Finally, he argues that many of the objects in which common sense believes really exist, including artifacts and biological devices shaped by natural selection, and that we too exist, as products of natural selection. (shrink)

Lynne Rudder Baker presents and defends a unique account of the material world: the Constitution View. In contrast to leading metaphysical views that take everyday things to be either non-existent or reducible to micro-objects, the Constitution View construes familiar things as irreducible parts of reality. Although they are ultimately constituted by microphysical particles, everyday objects are neither identical to, nor reducible to, the aggregates of microphysical particles that constitute them. The result is genuine ontological diversity: people, bacteria, donkeys, mountains and (...) microscopes are fundamentally different kinds of things - all constituted by, but not identical to, aggregates of particles. Baker supports her account with discussions of non-reductive causation, vagueness, mereology, artefacts, three-dimensionalism, ontological novelty, ontological levels and emergence. The upshot is a unified ontological theory of the entire material world that irreducibly contains people, as well as non-human living things and inanimate objects. (shrink)

This paper describes a plausible view of the nature of physical objects, their mereological connections to each other, and their relation to spacetime. As well as being parsimonious, the view provides a plausible context for denying all of the following: (1) A theory that objects endure through time (and do not have temporal parts, as normally conceived) cannot claim that material objects are identical to space-time regions they occupy. (2) At least one of the family of mereological connections (part-whole, overlap (...) etc.) is to be taken as primitive. (3) Claims entirely in the language of quantifiers and identity and mereology are not semantically vague. It is thus an example showing that the there are more options for the metaphysics of objects, spacetime and mereology than many metaphysicians ordinarily assume. (shrink)

One pressing question facing Barnes andWilliams is that of which vari- eties of metaphysical indeterminacy can be can accommodated within their framework. In what remains, I shall examine whether their framework can allow that it sometimes metaphysically indeterminate whether an object exists. I shall begin by outlining an argument, due to Theodore Sider, to the conclusion that vague existence is impossible.

According to a popular line of reasoning, diachronic vagueness creates a problem for the endurantist conception of persistence. Some authors have replied that this line of reasoning is inconclusive, since the endurantist can subscribe to a principle of Diachronic Unrestricted Composition (DUC) that is perfectly parallel to the principle required by the perdurantist’s semantic account. I object that the endurantist should better avoid DUC. And I argue that even DUC, if accepted, would fail to provide the endurantist with the necessary (...) resources for explaining diachronic vagueness in familiar semantic terms. (shrink)

When I take off my glasses, the world looks blurred. When I put them back on, it looks sharpedged. I do not think that the world really was blurred; I know that what changed was my relation to the distant physical objects ahead, not those objects themselves. I am more inclined to believe that the world really is and was sharp-edged. Is that belief any more reasonable than the belief that the world really is and was blurred? I see more (...) accurately with my glasses on than off, so visual appearances when they are on have some cognitive priority over visual appearances when they are off. If I must choose which kind of visual appearance to take at face value, I will choose the sharp-edged look. But what should I think when I see a mist, which looks very blurred however well I am seeing? Indeed, why choose to take any of the looks at face value? Why not regard all the choices as illegitimate projections of ways of seeing the world onto the world itself? (shrink)