Read on relevance: a rejoinder.
John P. Burgess · Notre Dame Journal of Formal Logic · 1984
The chief difficulty confronting any commentator on "relevance" or "relevant" logic is the Protean character of relevantism, its tendency to assume ever new forms, especially in response to criticism.In a recent note [2] I criticized the original version of relevantism, found in [1] and other joint works of Anderson and Belnap.This version might be called paleorelevantism to distinguish it from the various neorelevantisms that have sprung up in recent years.My note has provoked replies from Mortensen [5] and Read [6].I have responded to Mortensen elsewhere [3], and will respond to Read here. PaleorelevantismThe Anderson-Belnap paleorelevantist position involved three theses.1. Dualism: There are two senses of disjunction, the truth-functional or "extensional" sense v, and a non-truth-functional or "intensional" sense + .Of argument forms involving disjunction, (A) below is valid for + and invalid for v; (B) below is valid for v and invalid for +.(A) poxq (B) q not p :.p or q :.q 2. Populism: Dualism is compatible with common sense and involves no revision of the logical practice of ordinary people.In commonsensical arguments of form (A), the disjunction is meant as intensional, while in commonsensical arguments of form (B), the disjunction is meant as extensional. Objectivism:The connection of relevance that distinguishes p + q from p V q is an objective (e.g., semantical or causal), not a subjective (e.g., epistemological or psychological) matter.(Passages from [1] justifying the attribution of objectivism to Anderson and Belnap were cited in [2]; Read has not challenged this attribution.)