Contributions to Logic

Abstract

Mill’s contributions to logic are spread over many writings, from his review of Whately’s Elements of Logic (1827), A System of Logic (1843; 8th ed., 1872), An Examination of Sir William Hamilton’s Philosophy (1865), especially chaps 15 to 23, and including the Inaugural Address at the University of St Andrews (1867). Mill explained logic as ‘the entire theory of the ascertainment of reasoned or inferred truth’ (Logic, II, 3, 8). He regarded formal, deductive, syllogistic logic (logic of consistency) as of lesser importance, as not relating to real inference; hence his more important contributions concern language (names, meaning, definition, ideal language) and induction (causality and inductive methods of discovery and proof of causal generalisations). Although the Logic is still an important, relevant work today, the contributions of various of Mill’s contemporaries and near-contemporaries, for example Boole, de Morgan and Frege, have influenced and have greater relevance to contemporary logical inquiries, while in induction there is an increasing awareness of the writings of Whewell, Jevons and other nineteenth-century inductive logicians, and hence a more accurate placing of Mill’s contributions.