Abstract

Few, if any, logicians deserve the title 'precursor of modern argumentation theory' more than the largely neglected English logician, Alfred Sidgwick. Sidgwick developed a coherent and original theory of argumentation with a distinctly 'mo dern' flavour. This paper outlines his idea of a 'negative' view of logic, an important aspect of which is the thesis that the distinctions and inference schemata of formal logic should not be applied as criteria of the validity or invalidity of natural language arguments, but rather 'rogatively'--as suggesting the kinds of objections or demands for clarification that are relevant at specific stages of a discussion.