I argue that Universalism (the thesis that mereological composition is unrestricted) entails Extensionalism (the thesis that sameness of composition is sufficient for identity) as long as the parthood relation is transitive and satisfies the Weak Supplementation principle (to the effect that whenever a thing has a proper part, it has another part disjoint from the first).

Consciousness and Mind presents David Rosenthal's influential work on the nature of consciousness. Central to that work is Rosenthal's higher-order-thought theory of consciousness, according to which a sensation, thought, or other mental state is conscious if one has a higher-order thought that one is in that state. The first four essays develop various aspects of that theory. The next three essays present Rosenthal's homomorphism theory of mental qualities and qualitative consciousness, and show how that theory fits with and helps sustain (...) the HOT theory. A crucial feature of homomorphism theory is that it individuates and taxonomizes mental qualities independently of the way we're conscious of them, and indeed independently of our being conscious of them at all. So the theory accommodates the qualitative character not only of conscious sensations and perceptions, but also of those which fall outside our stream of consciousness. Rosenthal argues that, because this account of mental qualities makes no appeal to consciousness, it enables us to dispel such traditional quandaries as the alleged conceivability of undetectable quality inversion, and to disarm various apparent obstacles to explaining qualitative consciousness and understanding its nature. Six further essays build on the HOT theory to explain various important features of consciousness, among them the complex connections that hold in humans between consciousness and speech, the self-interpretative aspect of consciousness, and the compelling sense we have that consciousness is unified. Two of the essays, one an extended treatment of homomorphism theory, appear here for the first time. There is also a substantive introduction, which draws out the connections between the essays and highlights their implications. (shrink)

According to Rosenthal’s Higher-Order Thought (HOT) theory of consciousness, first-order mental states become conscious only when they are targeted by HOTs that necessarily represent the states as belonging to self. On this view a state represented as belonging to someone distinct from self could not be a conscious state. Rosenthal develops this view in terms of what he calls the ‘thin immunity principle’ (TIP). According to TIP, when I experience a conscious state, I cannot be wrong about whether it is (...) I who I think is in that state. We first suggest that TIP is a direct consequence of the HOT theory. Next we argue that somatoparaphrenia—a pathology in which sensations are sometimes represented as belonging to other people—shows that TIP can be violated. This violation of TIP in turn shows that the HOT theory’s claim that conscious states are necessarily represented as belonging to self is in error. Rosenthal’s attempt to account for pathological cases is found to be inadequate when applied to somatoparaphrenia, and other possible defenses are also shown to be incapable of preserving TIP. We further conclude by suggesting that the HOT theory’s failing in this regard is not a failing that is peculiar to this theory of consciousness. (shrink)

Although the relationship of part to whole is one of the most fundamental there is, this is the first full-length study of this key concept. Showing that mereology, or the formal theory of part and whole, is essential to ontology, Simons surveys and critiques previous theories--especially the standard extensional view--and proposes a new account that encompasses both temporal and modal considerations. Simons's revised theory not only allows him to offer fresh solutions to long-standing problems, but also has far-reaching consequences for (...) our understanding of a host of classical philosophical concepts. (shrink)

This paper defends Mereological Universalism(the thesis that, for any set S of disjoint objects, there is an object that the members of S compose. Universalism is unpalatable to many philosophers because it entails that if there are such things as my left tennis shoe, W. V. Quine, and the Taj Mahal, then there is another object that those three things compose. This paper presents and criticizes Peter van Inwagen's argument against Universalism and then presents a new argument in favor of (...) Universalism. It turns out that the most reasonable way to resist the argument for Universalism is to deny the existence of artifacts; thus, if we believe in artifacts, we have no real choice other than to embrace Universalism. (shrink)

The relationship of part to whole is one of the most fundamental there is; this is the first and only full-length study of this concept. This book shows that mereology, the formal theory of part and whole, is essential to ontology. Peter Simons surveys and criticizes previous theories, especially the standard extensional view, and proposes a more adequate account which encompasses both temporal and modal considerations in detail. 'Parts could easily be the standard book on mereology for the next twenty (...) or thirty years.' Timothy Williamson, Grazer Philosophische Studien. (shrink)

The topic of this book is material objects. Like most interesting concepts, the concept of a material object is one without precise boundaries.

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.

This paper defends Mereological Universalism (the thesis that, for any set S of disjoint objects, there is an object that the members of S compose. Universalism is unpalatable to many philosophers because it entails that if there are such things as my left tennis shoe, W. V. Quine, and the Taj Mahal, then there is another object that those three things compose. This paper presents and criticizes Peter van Inwagen’s argument against Universalism and then presents a new argument in favor (...) of Universalism. It turns out that the most reasonable way to resist the argument for Universalism is to deny the existence of artifacts; thus, if we believe in artifacts, we have no real choice other than to embrace Universalism. (shrink)

(No abstract is available for this citation).

Mereological Universalism is the thesis that, for any disjoint Xs, the Xs automatically compose something. In his book, Material Beings, Peter van Inwagen provides an argument against Universalism that relies on the following crucial premiss: (F) If Universalism is true, then the Xs cannot ever compose two objects, either simultaneously or successively.1 I have argued elsewhere (Rea 1998) that van Inwagen’s defence of (F) fails because it relies on the false assumption that Universalism is incompatible with the view that, for (...) some Xs, what the Xs compose depends upon how the Xs are arranged. However, Matthew McGrath (1998) has recently provided a new – and in his opinion, better – formulation of van Inwagen’s argument for (F). Furthermore, he claims (contrary to what van Inwagen himself apparently thinks) that four of the ten assumptions listed at the outset of Material Beings are ‘jointly sufficient for the falsity of Universalism’. (1998: 121) Those assumptions, as they appear on page 121 of McGrath 1998, are as follows. (shrink)