Abstract

Today, "The Sorites paradox" is used to refer to a class of paradoxical arguments having a similar form. An example is: A man weighing 100 lbs. is thin; every man who is thin will remain thin if he gains an ounce. Therefore, a man weighing 100 lbs. will remain thin if he gains 400 lbs. What makes the argument paradoxical is that while it seems both to be valid and to have true premises, it clearly has a false conclusion. It is commonly agreed that the argument shows that we should not accept the second premise--the principle that thinness always tolerates the gaining of a mere ounce. One does not solve the Sorites, though, just by giving up this "tolerance" principle. In the first chapter of the thesis, I say what more is required: If the tolerance principle is not true, why are we unable to say which instance or instances of it are not true? Why are we so attracted by the tolerance principle in the first place? Can we, despite the paradox, maintain the thought that vague predicates have borderline cases, even though that thought seems to conflict with the denial of tolerance principles? Can we, despite the paradox, maintain in some revised form the thought that if two things are similar enough in a certain respect , they will have the same semantic status with regard to a related vague predicate ? ;In the second chapter of the thesis, I present and criticize some going solutions to the paradox. In particular, I argue that none of these solutions can be regarded as complete, since none provides an answer to all four of the questions set out in the first chapter. In the third chapter, I develop my own solution to the Sorites paradox: vague predicates are radically context-dependent, in the sense that they may express different properties on different occasions of use; in any context, a vague predicate expresses a property instantiated by both or neither of two things that are relevantly similar in that context. In this third chapter I show, on the one hand, how my account of the context-dependence of vague predicates contains the resources for providing a complete solution to the Sorites; and on the other hand, how many incomplete solutions could be coherently supplemented with this account. I conclude the thesis with a fourth chapter, in which I consider versions of the Sorites paradox thought to arise from the existence of phenomenal continua, and to which I do not extend the solution developed in chapter three. I argue that phenomenal continua do not provide a series of the sort required to get the paradox going--that is, a series of things, each of which looks the same as its neighbor, but not the same as more distant members of the series. The conclusion of the chapter is disjunctive: either there are no phenomenal continua, or we have infinite powers of discrimination. Either way, we are permitted to accept as true the claim that if two things look the same, then if one looks red , then so does the other