Online research in philosophy

According to one account, vagueness is "metaphysical." The friend of metaphysical vagueness believes that, for some object and some property, there can be no determinate fact of the matter whether that object exemplifies that property. A second account maintains that vagueness is due only to ignorance. According to the epistemic account, vagueness is explained completely by and is nothing over and above our not knowing some relevant fact or facts. These are the minority views. The dominant position maintains that there is a third possible variety of vagueness, linguistic vagueness. And, it goes on to insist, all vagueness is of this third variety. I shall argue, however, that linguistic vagueness is not a third variety of vagueness. Either it is a species of metaphysical vagueness or a kind of ignorance. And this, I argue, makes trouble for the claim that all vagueness is linguistic.

It is a common view that if composition as identity is true, then so is mereological universalism (the thesis that all objects have a mereological fusion). Various arguments have been advanced in favour of this: (i) there has been a recent argument by Merricks, (ii) some claim that Universalism is entailed by the ontological innocence of the identity relation, (or that ontological innocence undermines objections to universalism) and (iii) it is entailed by the law of selfidentity. After a preliminary introduction to the competing theories of persistence (necessary for a discussion of Merricks’ argument) I examine each in turn and demonstrate how they fail. I conclude that the prejudice that if composition as identity is true then Universalism is true, is unwarranted. Thus one motivation for believing Universalism is lost and those who believe composition as identity should now be receptive to some form of restricted composition.

A plausible desideratum for an account of the nature of objects, at, and across time, is that it accommodate the phenomenon of vagueness without locating vagueness in the world. A series of arguments have attempted to show that while universalist perdurantism – which combines a perdurantist account of persistence with an unrestricted mereological account of composition – meets this desideratum, endurantist accounts do not. If endurantists reject unrestricted composition then they must hold that vagueness is ontological. But if they embrace unrestricted composition they are faced with the problem of the many, and cannot plausibly accommodate vagueness. This paper disambiguates two related sub-problems of the problem of the many, and argues that universalist perdurantism is not superior to universalist endurantism with respect to either of these.

There’s an argument around from so-called “linguistic theories of vagueness”, plus some relatively uncontroversial considerations, to powerful metaphysical conclusions. David Lewis employs this argument to support the mereological principle of unrestricted composition, and Theodore Sider employs a similar argument not just for unrestricted composition but also for the doctrine of temporal parts. This sort of argument could be generalised, to produce a lot of other less palatable metaphysical conclusions. However, arguments to Lewis’s and Sider’s conclusions on the basis of considerations about vagueness are uncompelling, even if we accept the crucial premises about vagueness. And a good thing too, since the generalised form of the argument would prove far too much.

I attempt to block the Lewis-Sider argument from vagueness by defending the possibility of borderline composition. After presenting Sider’s argument against borderline composition, and explaining why many universalists have reason to resist the argument, I examine a suppressed premise of Sider’s argument that has been entirely overlooked in the literature and show that one who denies this premise can block the argument without incurring commitment to the vagueness of any logical vocabulary. I then examine the charge that proponents of borderline composition incur commitment to “ontic vagueness,” distinguish ten things that might be meant by this charge, and explain why the form of “ontic vagueness” to which they are committed is largely superficial and does not compromise the determinacy of the world as a whole.

David Lewis (1986) criticizes moderate views of composition on the grounds that a restriction on composition must be vague, and vague composition leads, via a precisificational theory of vagueness, to an absurd vagueness of existence. I show how to resist this argument. Unlike the usual resistance, however, I do not jettison precisificational views of vagueness. Instead, I blur the connection between composition and existence that Lewis assumes. On the resulting view, in troublesome cases of vague composition, there is an object, which definitely exists, about which it is vague whether the relevant borderline parts compose it.

A presentation of the Lewis-Sider argument from vagueness for unrestricted composition and possible responses.

says that there are some composite objects. And it says that some objects jointly compose nothing at all. The main threat to restricted composition is the in.uential and widely defended Vagueness Argument. We shall see that the Vagueness Argument fails. In seeing how this argument fails, we shall discover a new focus for the debate over composition's extent.

In this paper I offer a counterexample to the so called vagueness argument against restricted composition. This will be done in the lines of a recent suggestion by Trenton Merricks, namely by challenging the claim that there cannot be a sharp cut-off point in a composition sequence. It will be suggested that causal powers which emerge when composition occurs can serve as an indicator of such sharp cut-off points. The main example will be the case of a heap. It seems that heaps might provide a very plausible counterexample to the vagueness argument if we accept the idea that four grains of sand is the least number required to compose a heap—the case has been supported by W. D. Hart. My purpose here is not to put forward a new theory of composition, I only wish to refute the vagueness argument and point out that we should be wary of arguments of its form.

other things, that the Vagueness Argument for unrestricted composition fails. In ‘Vagueness and Arbitrariness: Merricks on Composition’, Elizabeth Barnes objects to my argument. This paper replies to Barnes, and also offers further support for the views defended in my original paper.