It has frequently been suggested that quantum mechanics may provide a genuine case of ontic vagueness or metaphysical indeterminacy. However, discussions of quantum theory in the vagueness literature are often cursory and, as I shall argue, have in some respects been misguided. Hitherto much of the debate over ontic vagueness and quantum theory has centered on the “indeterminate identity” construal of ontic vagueness, and whether the quantum phenomenon of entanglement produces particles whose identity is indeterminate. I argue that this way (...) of framing the debate is mistaken. A more thorough examination of quantum theory and the phenomenon of entanglement reveals that quantum mechanics is best interpreted as supporting what I call the “vague property” construal of ontic vagueness, where vague properties are understood in terms of determinable properties without the corresponding determinates. (shrink)

On the one hand, philosophers have presented numerous apparent examples of indeterminate individuation, i.e., examples in which two things are neither determinately identical nor determinately distinct. On the other hand, some have argued against even the coherence of the very idea of indeterminate individuation. This paper defends the possibility of indeterminate individuation against Evans’s argument and some other arguments. The Determinacy of Identity—the thesis that identical things are determinately identical—is distinguished from the Determinacy of Distinctness—the thesis that distinct things are (...) determinately distinct. It is argued that while the first thesis holds universally and there is no case of indeterminate identity, there are reasons to think that the second thesis does not hold universally, and that there are cases of indeterminate distinctness. (shrink)

Can we solve the Problem of the Many, and give a general account of the indeterminacy in definite descriptions that give rise to it, by appealing to metaphysically indeterminate entities? I argue that we cannot. I identify a feature common to the relevant class of definite descriptions, and derive a contradiction from the claim that each such description is satisfied by a metaphysically indeterminate entity.

On the opposition between de re and de dicto conceptions of vagueness, with special reference to their bearing on the tasks of ontology.

We presume a background theory which allows for indeterminacy of states of affairs involving objects, extending even to indeterminacy of identity between objects. A sentence reporting such an indeterminate state of affairs lacks truth-value. We extend this to a theory of sets, similar to ZFU, in which membership in, and identity between, sets may also be indeterminate.

Traditionally, this puzzle has been solved in various ways. Aristotle, for example, distinguished between “accidental” and “essential” changes. Accidental changes are ones that don't result in a change in an objects' identity after the change, such as when a house is painted, or one's hair turns gray, etc. Aristotle thought of these as changes in the accidental properties of a thing. Essential changes, by contrast, are those which don't preserve the identity of the object when it changes, such as when (...) a house burns to the ground and becomes ashes, or when someone dies. Armed with these distinctions, Aristotle would then say that, in the case of accidental changes, (1) and (2) are both false—a changing thing can really change one of its “accidental properties” and yet literally remain one and the same thing before and after the change. (shrink)

In this paper I present a new argument against vague identity — one that is more fundamental than existing arguments — and I also try to explain why we find the idea of vague identity puzzling, in a way that will dispel the puzzlement. In brief, my argument is this: to make clear sense of something, one must at least model it set-theoretically; but due to the special place of identity in set-theoretic models, any vague relation that one does model (...) set-theoretically will not be identity, for real identity will already be there, built into the background of the model, and perfectly precise. (shrink)

Various arguments have recently been put forward to support the existence of vague or fuzzy objects. Nevertheless, the only possibly compelling argument would support, not the existence of vague objects, but indeterminately existing objects. I argue for the non‐existence of any vague entities—either particulars or properties ‐ in the mind‐independent world. Even so, many philosophers have claimed that to reduce vagueness to semantics is of no avail, since linguistic vagueness betrays semantic incoherence and this is no less a problem than (...) is ontological incoherence. After spelling out why there are fewer essentially vague concepts than usually thought. I claim that only the linguistic competence of the whole speaking community for each word can draw the sharp boundaries for its concept, even if these are unknowable in practice and still leave a precise range of indetermination. This could explain both the existence of boundaries and our non‐removable ignorance of them, fulfilling the intuitions of the epistemic theory of vagueness with the supervaluationist's indeterminacy. (shrink)

Persistence in Time No person ever steps into the same river twice—or so goes the Heraclitean maxim. Obscure as it is, the maxim is often taken to express two ideas. The first is that everything always changes, and nothing remains perfectly similar to how it was just one instant before. The second is that nothing … Continue reading Persistence in Time →.

In this dissertation, I argue that vagueness is a metaphysical phenomenon---that properties and objects can be vague---and propose a trivalent theory of vagueness meant to account for the vagueness in the world. In the first half, I argue against the theories that preserve classical logic. These theories include epistemicism, contextualism, and semantic nihilism. My objections to these theories are independent of considerations of the possibility that vagueness is a metaphysical phenomenon. However, I also argue that these theories are not capable (...) of accommodating metaphysical vagueness. As I move into my positive theory, I first argue for the possibility of metaphysical vagueness and respond to objections that charge that the world cannot be vague. One of these objections is Gareth Evans' much-disputed argument that vague identities are impossible. I then describe what I call the logic of states of affairs. The logic of states of affairs has as its atomic elements states of affairs that can obtain, unobtain, or be indeterminate. Finally, I argue that the logic of states of affairs is a better choice for a theory of vagueness than other logics that could accommodate metaphysical vagueness such as supervaluationism and degree theories. Preference should be given to the logic of states of affairs because it provides a better explanation of higher-order vagueness and does a better job of matching our ordinary understandings of logical operators than supervaluationism does and because it provides a more general account of indeterminacy than the account given by degree theories. Advisor: Reina Hayaki. (shrink)

My paper provides reasons in support of the view that vague identity claims originate from a conflict between rigidity and precision in designation. To put this stricly, let x be the referent of the referential terms P and Q. Then, that the proposition “that any x being both a P and a Q” is vague involves that the semantic intuitions at work in P and Q reveal a conflict between P and Q being simultaneously rigid and precise designators. After having (...) shortly commented on an example of vague identity claim, I make the case for my proposal, by discussing how reference by baptism conflicts with descriptive attitudes towards understanding conceptual contents. (shrink)

In his seminal paper, ‘Can There Be Vague Objects?’ (1978), Gareth Evans advanced an argument purporting to prove that the idea of indeterminate identity is incoherent. Aware that his argument was incomplete as it stands, Evans added a remark at the end of his paper, in which he explained how the original argument needed to be modified to arrive at an explicit contradiction. This paper aims to develop a modified version of Evans’ original argument, which I argue is more promising (...) than the modification that Evans proposed in his remark. Last, a structurally similar argument against the idea of indeterminate existence is presented. (shrink)

Disagreeing with most authors on vagueness, the author proposes a solution that he calls ‘three-valued semantic pluralism’ to the age-old sorites paradox. In essence, it is a three-valued semantics for a first-order vague language with identity with the additional suggestion that a vague language has more than one correct interpretation. Unlike the traditional three-valued approach to a vague language, three-valued semantic pluralism can accommodate the phenomenon of higher-order vagueness and the phenomenon of penumbral connection when equipped with ‘suitable conditionals’. The (...) author also shows that three-valued semantic pluralism is a natural consequence of a restricted form of the Tolerance principle ) and a few related ideas, and argues that ) is well-motivated by considerations about how we learn, teach, and use vague predicates. (shrink)

ABSTRACTI propose a different account of fictional objects from the ones already present in the literature. According to my account, fictional objects are culturally created abstract objects dependent for their existence on the pretence attitude adopted by a group of people towards a single fictional content. My work is divided into three parts: in the first one, I present how fictional objects come into existence according to my proposal; in the second part, I illustrate how the existence of fictional objects (...) so conceived may be ontically indeterminate; in the last part, I consider what happens when vague existence and indeterminate identity are claimed within fictional texts. (shrink)

That grass is green, that pigs don’t fly, and that you are now awake are all hard facts. But there is often said to be something soft about matters of identity over time. Is today’s village church the very church that was first built here, despite centuries of repairs and alterations? How many parts of my bicycle do I need to replace before I get a numerically different bike? If a club disbands and years later some of the original members (...) start a similar club with the same name, have we got two clubs, or one club with a discontinuous history? It is tempting to say that there are no hard answers to these questions laid up in heaven. There is no determinate fact of the matter. Those who disagree about such things are arguing about words, not facts. We are free to say what we like. (shrink)