Remarks on the Modal Logic of Henry Bradford Smith

H. B. Smith, Professor of Philosophy at the influential Pennsylvania School was (roughly) a contemporary of C. I. Lewis who was similarly interested in a proper account of implication. His research also led him into the study of modal logic but in a different direction than Lewis was led. His account of modal logic does not lend itself as readily as Lewis' to the received possible worlds semantics, so that the Smith approach was a casualty rather than a beneficiary of the renewed interest in modality. In this essay we present some of the main points of the Smith approach, in a new guise.