Abstract/Summary

The Tractatus is widely held as showing that logic is a sui generis discipline, independent of the empirical and the psychological. Logic deals in tautologies, independent of and not representative of the world, and true in all circumstances. The logic proposed is however deemed to be irreparably flawed because the key notion object is inconsistent/unsatisfiable, and because elementary propositions are not independent of one another (colour exclusion problem). The argument presented aims to reconstruct the logic offered within the resources available in the text to show that Wittgenstein was aware of these difficulties and that he had responses to them. Chapter 1 presents logic as Wittgenstein inherited it from Russell, as universalist, non-psychologistic, and somehow related to science. Chapters 2 and 3 consider the logical system as formal/uninterpreted, but as intended to be applicable and thus consistent. Tensions between logic as wholly sui generis or as somehow involved in the empirical are discussed. What is formal and what is empirical, and what is necessary and what accidentally general, are clearly demarcated. Chapter 4 relates to tensions between objects as nameable individuals, and the context principle. It is argued that Wittgenstein does not think in familiar terms of quantification/first-order logic. A critical difference between Russellian propositional functions and Tractarian functions, and between quantification and generalisation, is brought out. Chapters 5, 6, and 7 discuss logical space as a space of possibilities, and how this together with the logical treatment of probability enables a probabilistic account of laws of nature. The account relies on totalities of objects and propositions, deploying S5B. In Chapter 8 models are presented based on nineteenth century structural chemistry (for objects) and a relational view of space (exclusion problems) to show how the logical system can be regarded as consistent.