An encyclopedia entry which covers various revisionary conceptions of which macroscopic objects there are, and the puzzles and arguments that motivate these conceptions: sorites arguments, the argument from vagueness, the puzzles of material constitution, arguments against indeterminate identity, arguments from arbitrariness, debunking arguments, the overdetermination argument, and the problem of the many.

The Special Composition Question may be formulated as follows: for any xs whatsoever, what are the metaphysically necessary and jointly sufficient conditions in virtue of which there is a y such that those xs compose y? But what is the scope of the sought after explanation? Should an answer merely explain compositional facts, or should it explain certain ontological facts as well? On one natural reading, the question seeks an explanation of both the compositional facts and the ontological; the question (...) seeks to explain how composite objects exist; how there is a y such that the xs compose y. But it turns out that some answers to the Special Composition Question presuppose those ontological facts rather than explain those ontological facts. In this paper, I will indicate what I take to be the different explanatory demands met by the representative answers. I will argue that the wide scope explanatory demands can’t be satisfied. I will also show that this result has bearing on the current debate about composition. (shrink)

According to the so-called strong variant of Composition as Identity (CAI), the Principle of Indiscernibility of Identicals can be extended to composition, by resorting to broadly Fregean relativizations of cardinality ascriptions. In this paper we analyze various ways in which this relativization could be achieved. According to one broad variety of relativization, cardinality ascriptions are about objects, while concepts occupy an additional argument place. It should be possible to paraphrase the cardinality ascriptions in plural logic and, as a consequence, relative (...) counting requires the relativization either of quantifiers, or of identity, or of the is one of relation. However, some of these relativizations do not deliver the expected results, and others rely on problematic assumptions. In another broad variety of relativization, cardinality ascriptions are about concepts or sets. The most promising development of this approach is prima facie connected with a violation of the so-called Coreferentiality Constraint, according to which an identity statement is true only if its terms have the same referent. Moreover - even provided that the problem with coreferentiality can be fixed - the resulting analysis of cardinality ascriptions meets several difficulties. (shrink)

I defend the thesis that Composition Entails Identity (CEI): that is, a whole is identical to all of its parts, taken together. CEI seems to be inconsistent, since it seems to require that the parts of a whole possess incompatible number properties (for instance, being one thing and being many things). I show that these number properties are, in fact, compatible.

Composition as identity is the view that a whole is identical to its parts taken collectively. Such a view raises the question of how the same portion of reality can be both one thing and many things. A primitivist view holds that there is no explanation to be had and that we simply need to accept that being one thing and being many things are compatible. One might think that we can do better by resorting to relativization. A relativist view (...) may seem to explain how the same portion of reality can be both one thing and many things on the basis of the assumption that the portion of reality is these ways relative to different ‘concepts’ or ‘counts’. This paper discusses whether relativization truly leads to a satisfactory explanation of how something can be both one thing and many things. The conclusion will be that, when we consider the current accounts of the involved parameters, these relativizations make no explanatory progress. (shrink)