Ludwig Wittgenstein's Change of View

Excerpt From: Monk, Ray. "Ludwig Wittgenstein The Duty of Genius"

In his discussions with Schlick and Waismann during the Christmas vacation, Wittgenstein outlined some of the ways in which his views had changed since he had written the Tractatus. He explained to them his conviction that the Tractatus account of elementary propositions was mistaken, and had to be abandoned – and, with it, his earlier view of logical inference:

… at that time I thought that all inference was based on tautological form. At that time I had not seen that an inference can also have the form: This man is 2m tall, therefore he is not 3m tall.‘What was wrong about my conception’, he told them, ‘was that I believed that the syntax of logical constants could be laid down without paying attention to the inner connection of propositions.’ He now realized, though, that the rules for the logical constants form only a part of ‘a more comprehensive syntax about which I did not yet know anything at the time’. His philosophical task now lay in describing this more complicated syntax, and in making clear the role of ‘internal connections’ in inference.

His thoughts on how he was to accomplish this task were, at this time, in a state of flux, changing from one week to the next, and even from one day to the next. A feature of these conversations is how often Wittgenstein begins his remarks with comments like ‘I used to believe …’, ‘I have to correct my account …’, ‘I was wrong when I presented the matter in this way …’, referring, not to positions he had taken in the Tractatus, but to views he had expressed earlier in the year, or, perhaps, earlier in the week.

As an example of what he meant by ‘syntax’ and of the internal connections it established, he imagined someone’s saying: ‘There is a circle. Its length is 3cm and its width is 2cm.’ To this, he says, we could only reply: ‘Indeed! What do you mean by a circle then?’ In other words, the possibility of a circle that is longer than it is wide is ruled out by what we mean by the word ‘circle’. These rules are provided by the syntax, or, as Wittgenstein also says, the ‘grammar’ of our language, which in this case establishes an ‘internal connection’ between something’s being a circle and its having only one radius.

The syntax of geometrical terms prohibits, a priori, the existence of such circles, just as the syntax of our colour words rules out the possibility of a thing’s being both red and blue. The internal connections set up by these different grammars allow the kind of inferences that had eluded analysis in terms of the tautologies of the Tractatus, because each of them forms a system:

Once I wrote [TLP 2.1512], ‘A proposition is laid against reality like a ruler…’ I now prefer to say that a system of propositions is laid against reality like a ruler. What I mean by this is the following. If I lay a ruler against a spatial object, I lay all the graduating lines against it at the same time. 

If we measure an object to be ten inches, we can also infer immediately that it is not eleven inches etc.

In describing the syntax of these systems of propositions, Wittgenstein was coming close to, as Ramsey had put it, outlining certain ‘necessary properties of space, time, and matter’. Was he, then, in some sense, doing physics? No, he replies, physics is concerned with determining the truth or falsity of states of affairs; he was concerned with distinguishing sense from nonsense. ‘This circle is 3 cm long and 2 cm wide’ is not false, but nonsensical. The properties of space, time and matter that he was concerned with were not the subject of a physical investigation, but, as he was inclined to put it at this time, a phenomenological analysis. ‘Physics’, he said, ‘does not yield a description of the structure of “phenomenological states of affairs. In phenomenology it is always a matter of possibility, i.e. of sense, not of truth and falsity.'

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