It has been argued by some that the argument from vagueness is one of the strongest arguments in favor of the theory of temporal parts. I will neither support nor dispute this claim here. Rather, I will present a version of the argument from vagueness, which – if successful – commits one to the existence of modal parts. I argue that a commitment to the soundness of the argument from vagueness for temporal parts compels one to commit to the soundness (...) of the argument from vagueness for modal parts. I say compels, but not entails; an objection to one of the arguments highlights analogous ways to reject the other, making it difficult to endorse one and reject the other. This would be a significant conclusion, if true, since there are far fewer who currently commit themselves to modal parts than the many who currently commit themselves to temporal parts. (shrink)

Lewis famously argued that mereology is ontologically innocent. Many who have considered this claim believe he was mistaken. Mereology is not innocent, because its acceptance entails the acceptance of sums, new objects that were not previously part of one’s ontology. This argument, the argument from ontological parsimony, has two versions: a qualitative and a quantitative one. I argue that the defender of mereology can neutralize both arguments by holding that, given mereology, a commitment to the parts of an object is (...) not an extra ontological commitment, made in addition to the commitment to the object; and that if the parts of an object are ‘ontologically innocent’, then sums cannot fail to be innocent either. (shrink)

According to ‘composition as identity’, a composite object is identical to all its parts taken together. Thus, a plurality of composite objects is identical to the plurality of those objects’ parts. This has the consequence that, e.g., the bricks which compose a brick wall are identical to the atoms which compose those bricks, and hence that the plurality of bricks must include each of those atoms. This consequence of CAI is in direct conflict with the standard analysis of plural definite (...) descriptions. According to that analysis, the denotation of ‘the bricks’ can include only bricks. It seems, then, that if CAI is true, ‘the bricks’ doesn’t denote anything; more generally, if CAI is true, there are fewer pluralities than we ordinarily think. I respond to this argument by developing an alternative analysis of plural descriptions which allows the denotation of ‘the bricks’ to include non-bricks. Thus, we can accept CAI, while still believing in all the pluralities we could want. As a bonus, my approach to plural descriptions and plural comprehension blocks recent arguments to the effect that CAI entails compositional nihilism. (shrink)

What is the relation between parts taken together and the whole that they compose? The recent literature appears to be dominated by two different answers to this question, which are normally thought of as being incompatible. According to the first, parts taken together are identical to the whole that they compose. According to the second, the whole is grounded in its parts. The aim of this paper is to make some theoretical room for the view according to which parts ground (...) the whole they compose while being, at the same time, identical to it. (shrink)

When the necessity of identity (NI) is combined with composition as identity (CAI), the contingency of composition (CC) is at risk. In the extant literature, either NI is seen as the basis for a refutation of CAI or CAI is associated with a theory of modality, such that: either NI is renounced (if counterpart theory is adopted); or CC is renounced (if the theory of modal parts is adopted). In this paper, we investigate the prospects of a new variety of (...) CAI, which aims to preserve both NI and CC. This new variety of CAI (CCAI, contingent composition as identity) is the quite natural product of the attempt to make sense of CAI on the background of a broadly Kripkean view of modality, such that one and the same entity is allowed to exist at more than one possible world. CCAI introduces a world-relative kind of identity, which is different from standard identity, and claims that composition is this kind of world-relative identity. CCAI manages to preserve NI and CC. We compare CCAI with Gibbard’s and Gallois’ doctrines of contingent identity and we show that CCAI can be sensibly interpreted as a form of Weak CAI, that is of the thesis that composition is not standard identity, yet is significantly similar to it. (shrink)

‘It feels like I have lost a part of myself’ is frequently uttered by those grieving the death of a loved one. Despite the ubiquity of such utterances, and the palpable sense that they express something true, few philosophers have considered what, if anything, accounts for their truth. Here, I develop a suggestion from Donald Baxter according to which Composition as Identity provides us a means to understand the grief utterances literally. In doing so, I identify and develop a version (...) of Leibniz's Law required for Composition as Identity to account for the truth of the grief utterances. In turn, this principle helps shed light on Composition as Identity's central claim: that the parts are identical to the whole. By considering objections to the resulting view, I construct a list of desiderata for other philosophers interested in accounting for the grief utterances. (shrink)

According to strong composition as identity, the logical principles of one–one and plural identity can and should be extended to the relation between a whole and its parts. Otherwise, composition would not be legitimately regarded as an identity relation. In particular, several defenders of strong CAI have attempted to extend Leibniz’s Law to composition. However, much less attention has been paid to another, not less important feature of standard identity: a standard identity statement is true iff its terms are coreferential. (...) We contend that, if coreferentiality is dropped, indiscernibility is no help in making composition a genuine identity relation. To this aim, we analyse as a case study Cotnoir’s theory of general identity, in which indiscernibility is obtained thanks to a revisionary semantics and true identity statements are allowed to connect non-coreferential terms. We extend Cotnoir’s strategy for indiscernibility to the relation of comaternity, and we show that, neither in the case of composition nor in that of comaternity, indiscernibility contibutes to show that they are genuine identity relations. Finally, we compare Cotnoir’s approach with other versions of strong CAI endorsed by Wallace, Bøhn, and Hovda, and canvass the extent to which they violate coreferentiality. The comparative analysis shows that, in order to preserve coreferentiality, strong CAI is forced to adopt a non-standard semantic treatment of the singular/plural distinction. (shrink)

This paper provides new arguments for the following claim: either strong composition as identity cannot retain the full strength of both the logical principles of one-one identity and its semantical principles or it only delivers cases of boring composition in that it entails mereological nihilism.

Composition as Identity is the thesis that a whole is, strictly and literally, identical to its parts, considered collectively. McDaniel [2008] argues against CAI in that it prohibits emergent properties. Recently Sider [2014] exploited the resources of plural logic and extensional mereology to undermine McDaniel’s argument. He shows that CAI identifies extensionally equivalent pluralities – he calls it the Collapse Principle – and then shows how this identification rescues CAI from the emergentist argument. In this paper I first give a (...) new generalized version of both the arguments. It is more general in that it does not presuppose an atomistic mereology. I then go on to argue that the consequences of CP are rather radical. It entails mereological nihilism, the view that there are only mereological atoms. I finally show that, given a mild assumption about property instantiation, namely that there are no un-instantiated properties, this argument entails that CAI and emergent properties are incompatible after all. (shrink)

Mereological nihilism (henceforth just "nihilism") is the thesis that composition never occurs. Nihilism has often been defended on the basis of its theoretical simplicity, including its ontological simplicity and its ideological simplicity (roughly, nihilism's ability to do without primitive mereological predicates). In this paper I defend nihilism on the basis of the theoretical unification conferred by nihilism, which is, roughly, nihilism's capacity to allow us to take fewer phenomena as brute and inexplicable. This represents a respect in which nihilism enjoys (...) greater theoretical simplicity than its rivals which has not yet been explored, and which is immune to many of the objections which have been leveled against previous arguments for nihilism from nihilism's theoretical simplicity. Composition as identity might be thought to confer a similar degree of theoretical unification as nihilism. I end the paper by arguing that this is not the case. (shrink)

According to Lewis, mereology is the general and exhaustive theory of ontological composition, and every contingent feature of the world supervenes upon some fundamental properties instantiated by minimal entities. A profound analogy can be drawn between these two basic contentions of his metaphysics, namely that both can be intended as a denial of emergentism. In this essay, we study the relationships between Humean supervenience and two philosophical spin-offs of mereological monism: the possibility of gunk and the thesis of composition as (...) identity. In a gunky scenario, there are no atoms and, thus, some criteria alternative to mereological atomicity must be introduced in order to identify the bearers of fundamental properties; this introduction creates a precedent, which renders the restriction of the additional criteria to gunky scenarios arbitrary. On the other hand, composition as identity either extends the principle of indiscernibility of identicals to composition or is forced to replace indiscernibility with a surrogate; both alternatives lead to the postulation of a symmetric kind of supervenience which, in contrast to Humean supervenience, does not countenance a privileged level. Both gunk and composition as identity, thus, display a tension with Humean supervenience. (shrink)

In this paper, I present the thesis of Composition as Identity as I think it should be understood, and reply to some objections to it. My aim is not to argue that CAI is true, but to show how CAI can be true, and push the debate forward in the direction I think it must and should go in light of some new objections.

A material composite object is an object composed of two or more material parts. The world, it seems, is simply awash with such things. The Eiffel Tower, for instance, is composed of iron girders, nuts and bolts, and so on. You and I, as human beings, are composed of flesh and bone, and various organs. Moreover, these parts themselves are composed of further parts, such as molecules, which themselves are composed of atoms, which are composed of sub-atomic particles. Material composite (...) objects are, it seems, ubiquitous. However, despite their ubiquity, a little philosophical reflection on the matter, as is so often the case, reveals that they are also deeply puzzling. -/- The question which has received most attention from philosophers interested in material composition is: under what circumstances do two or more material objects compose a further object? Why is it, for instance, that a collection of iron girders that are bolted together in the centre of Paris do compose an object (that is, the Eiffel Tower), but that there is no object composed of the Eiffel Tower and the Moon? What conditions are satisfied by the first set of objects, and not by the second set of objects, which make this the case? In short, what are the necessary and sufficient conditions for composition to occur? -/- Since the 1980s, philosophers have devoted considerable attention to this question, and it has proved difficult to answer. This article provides a survey of the various answers that have been given to this question, plus the arguments that have been offered in their defence. (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)

In Parts of Classes David Lewis attempts to draw a sharp contrast between mereology and set theory and he tries to assimilate mereology to logic. For him, like logic but unlike set theory, mereology is “ontologically innocent”. In mereology, given certain objects, no further ontological commitment is required for the existence of their sum. On the contrary, by accepting set theory, given certain objects, a further commitment is required for the existence of the set of them. The latter – unlike (...) the sum of the given objects – seems to be an abstract entity whose existence is not directly entailed by the existence of the objects themselves. The argument for the innocence of mereology is grounded on the thesis of composition as identity. In our paper we argue that: arguments for the ontological innocence of mereology are not conclusive. Some arguments against the ontological innocence of mereology show a certain ambiguity in the innocence thesis itself. The innocence thesis seems to depend on a general conception of the nature of objects and on how the notion of ontological commitment is understood. Specifically, we think that the thesis is the manifesto of a realistic conception of parts and sums. Quine‟s notorious criticism of the set-theoretical interpretation of second order logic seems to be reproducible against Lewis‟defence of mereology. To the purpose we construct a mereological model of a substantive fragment of set theory, adequate to ground the set-theoretical semantics of second order logic. (shrink)

I argue that Composition as Identity blocks the plural version of Cantor's Theorem, and that therefore the plural version of Cantor's Theorem can no longer be uncritically appealed to. As an example, I show how this result blocks a recent argument by Hawthorne and Uzquiano.