Ruling out the Sorites: Vagueness, Rules, Wittgenstein
by
Justin Johann Hans-Hermann Needle
Thesis submitted for the degree of PhD in Philosophy
University of Dundee
October 1995
Abstract
After clarifying the philosophical notion of vagueness I discuss what Crispin Wright has called the Governing View of language, according to which speakers' linguistic competence is to be explained in terms of their grasp of rules for the correct use of expressions of their language. This view has been rejected by Wright and others on grounds of incoherence, since the rules which it posits for observational expressions appear to be susceptible to versions of the Sorites paradox (or the Paradox of the Heap).
Some well-known responses to the paradox are discussed and rejected, and Wright's own preferred approach, which involves dropping the assumption that observational expressions are rule-governed and replacing it with a more behaviouristic or statistical account of language mastery - involving the notion of response-dependence - is criticized in detail.
The nature of rules, in particular semantic rules, is then examined, and it is argued that we cannot dispense with the notion of a semantic rule in any adequate account of human linguistic ability.
Another recent attempt to solve the Sorites, due to Linda Burns, is also criticized, and further paradoxical problems are introduced, relating this time to the notions of
judgment and justification.
So we arrive at an impasse which, it is argued, may be overcome by adopting the later Wittgenstein's account of rules, rule-following and justification. The conclusion is that the supposition that a speaker's use of language is governed by rules is not, after all, paradoxical, even for the 'problematic' class of observational expressions. This conclusion does, however, involve abandoning a certain dominant, rationalistic conception of the foundations of language and of the nature of language mastery.
Finally, an interpretation is offered of Wittgenstein's use of the term 'criterion', a species of rule which plays a pivotal role in his later philosophy of language. A number of rival accounts of the notion are rejected, and it is shown how criteria are connected with, and shed light upon, Wittgenstein's general approach to language and rules, and his distinctive philosophical methodology.