Abstract

In truth-functional analysis we need not worry about the purported ambiguity of the English ‘or,’ for we can assign different symbols and define each by means of a truth table. However, at least in classes in elementary logic, we often try to indicate that there is some rationale to the assignation of truth values by marshaling English disjunctive sentences which will clearly render an inclusive or an exclusive reading, without the explicit addition of one of the qualifying phrases, “or both” or “but not both.” At this point one discovers people writing on logic saying quite different things about the English ‘or.’ In his Methods of Logic Quine takes the inclusive sense to be the more naturally intended and claims that “indisputable instances of the exclusive use” are rare. Yet in The Principles of Logic Bradley says that no one ever really intends to use ‘or’ in any other than an exclusive sense; and Bosanquet followed him in this. In this paper I am interested in attempting to discover why the British Idealists held that ‘or’ is always exclusive, especially in the face of various examples which, prima facie, establish both uses in English. Why would Bradley feel compelled to deny “any possible instance in which alternatives are not exclusive”? As it turns out, the position held by Bradley and Bosanquet is stronger and more interesting than one initially expects.