The Relevance of Logic to Reasoning and Beleif Revision: Harman on ‘Change in View’


  • William Max Knorpp


In Change of View: Principles of Reasoning, Gilbert Harman argues that (i) all genuine reasoning is a matter of belief revision, and that, since (ii) logic is not “specially relevant” to belief revision, (iii) logic is not specially relevant to reasoning, either. Thus, Harman suggests, what is needed is a “theory of reasoning”–which, incidentally, will be psychologistic, telling us both how we do and how we should reason. I argue that Harman fails to establish the need for such a theory, because (a) reasoning is not always a matter of belief revision, and (b) logic is, in fact, of the utmost relevance to both reasoning and belief revision.