The Logic of Practical Reasoning

Abstract

The aim of this chapter is to clarify the formal logic appropriate for practical reasoning. Several theories of practical reasoning have been proposed in recent years, of which Kenny’s theory, discussed in the last chapter, is a representative example. Although in criticizing Kenny’s theory I raised no doubts about the need for a special logic, involving special operators like Kenny’s ‘Fiat(…)’, I shall argue that practical reasoning can be interpreted as requiring no more than ordinary ’assertoric’ first-order logical principles. My view here is not based on general considerations or on philosophical ideology. I think there is a good prima facie case for a special logic of practical inference, and any dissenting view, such as mine, requires careful, detailed defense. I shall therefore proceed by considering important alternative views and develop my own position in the process of criticizing them.