ABSTRACT
Frequently in the preceding chapters we have used illustra tive symbols.* The use of such symbols is not logically essential but it is convenient and is probably psychologically indispensable to enable us to concentrate our attention upon the form of propositions. Illustrative symbols are by no means confined to logic and mathematics. They are em ployed in ordinary speech when we use pronouns. For instance, suppose you are listening to the news on the wireless and are in a room with several people, some of whom are not anxious to hear v/hat is said. There is a murmured buzz of low-toned conversation. You say: T can’t hear; someone is saying something; it may be important but can’t it wait till after the news?’ Here “ I ” stands for the speaker and is definitely specified for anyone who knows who is speaking; “ someone is saying something” does not specify who says what\ these pronouns are illustrative symbols standing for one person in the class of persons in the room but an unspecified one. Suppose now you say, ‘Jack, it is you who are talking’, then “ Jack” names an individual, i.e. the illustrative symbol “ someone” has been replaced by a specified individual’s name “ Jack” . In contrast with the indefinite pronoun “ some one” we call “ Jack” a constant, for it signifies the same indi vidual throughout every occasion of its use (provided we make the assumption that there is only one person named “Jack” in the set to which reference is being made). Personal pronouns may also be used indefinitely when the person to whom reference is made is not specified. In this book “ I ”
and “ you” have been thus used to stand for any one person (the speaker, questioner, etc.) and for any one other person (the hearer, answerer, etc.), respectively.* “ He” is often so used to stand for some unspecified murderer (at least by detectives in fiction), also in legal documents and in various expositions, and in some places in this book, where “ he” could be interpreted in some contexts as standing for a female. We are so used to these conventions that we find no difficulty in understanding what is meant. (“ We” in the preceding sentence is used in an illustrative way even though one person denoted by “ we” is /, Susan Stebbing.) There is no more diffi culty in understanding variable symbols than in under standing how pronouns are used. Statements in which pro nouns are used will be ambiguous unless the context specifies the range of their application; this is usually the case, but sometimes difficulties arise through failure in specification.
