Abstract

In this article the author gives a systematical exposition and interpretation of the concept of a tautology in Wittgenstein's 'Tractatus'. The following questions are discussed successively : 1. What is, according to Wittgenstein, a tautology ? The answer to this question is given by means of an exposition of the definition of 'tautology' in 4.46. The tautology appears to be that result of the manipulation with truth-tables which cancels itself. Within this scope an interpretation is given of the words 'Tatsache', 'Sachverhalt', 'Sachlage' and others, in which the first two are considered to mean 'piece of reality' and the last 'possible piece of reality'. Some methods of recognizing a tautology are treated, especially that of 6.1203. 2. What is the difference between a tautology and the other propositions of language ? Much attention is paid to the use of the word 'truth' in the 'Tractatus', which has three important meanings : a. (possibility of) agreement of (elementary) propositions with reality ; b. agreement of (molecular) propositions with their thrutharguments ; apriorical truth of the tautology. Wittgenstein's theory of probability is explained by means of some examples. 3. Why the propositions of logic are they tautologies ? After a discussion of the theory of inference, in which an inference appears to be a reversed tautological implication, it is shown how Wittgenstein may gather his theory of the propositions of logic as tautologies from the theses discussed before : a. that a tautology is true for all the truth-possibilities of its elementary propositions ; b. that a tautology is unconditionally true ; c. that a tautology is senseless and says nothing, but shows the scaffolding of language ; d. that a tautology has always the probability 1 ; e. that inference is the reversed operation of making a tautology ; f. that inference and tautology are apriorical truths