On Stevenson's If-Iculties

Abstract

Professor Stevenson's valuable paper [5] calls attention to a number of discrepancies between ‘if’ in English and its usual translation into the horseshoe of material implication. “This is not a reason for distrusting the horseshoe,” he notes, “which is useful so long as it is taken to mean just what it is defined to mean; and it is not a reason for distrusting our English if's, which in spite of their ambiguities are indispensable to our daily discourse” ([5], p. 27). Accordingly, Stevenson proposes to develop a “richer logic” than the ordinary one, by adding as primitives certain sentential connectives. He speaks throughout in the old terminology of “propositions” rather than in that of the sentences or statements used to express them. Thus he speaks of atomic and molecular propositions, somehow no doubt as real entities in the world, where talk of atomic and molecular sentences would save him from implicit involvement in the notorious difficulties connected with atomic facts. Finally, the inner structure of atomic sentences, and therewith of molecular ones, is never considered. Many molecular sentences contain quantifiers in interesting ways, the clarification of which would seem essential in getting at their structure. Stevenson, however, has no concern with quantifiers, and does not exhibit the quantificational structure of the English sentences considered.