6.53 The right method for philosophy would properly be this: To say nothing other than what can be said, thus propositions of natural science – thus something that has nothing to do with philosophy –, and then always, if another wanted to say something metaphysical, to point out to him that he had given no meaning to certain signs in his propositions. This method would be unsatisfying for the other person – he would not have the feeling that we were teaching him philosophy – but it would be the only strictly correct one.
Not the method used in the Tractatus, apparently (it does not seem to consist solely of propositions of natural science, after all), but perhaps the one used (in attempt, at least) by certain Wittgensteinians. Why does he not use it here? It is an ad hominem method, and here he wants a general approach. He, as it were, demonstrates a method, by examples. But it also is somewhat ad hominem, with Frege and Russell being the most obvious targets.
How would the strictly correct method be justified? The demonstration of a method (or methods) works, if at all, by being shown or found to be successful. If the aim is clarity, then the method would be justified by being shown to lead to clarity.
Consider the method advocated here in possible application to Frege. Frege never defines “course-of-values.” See Basic Laws vol. 2 §146. He says it cannot be defined, even though he uses the concept a lot and introduces it as early as §3. All that he can do, he says, is to give hints as to the meanings of such terms, and hope that the reader gets the idea. But in such cases, Weiner points out (see pp. 159-160 of Reck), it is possible that the author himself has failed to give a meaning to his term.
Anscombe (p. 151): “The criticism of sentences as expressing no real thought, according to the principles of the Tractatus, could never be of any very simple general form; each criticism would be ad hoc, and fall within the subject-matter with which the sentence professed to deal.” Wittgenstein is not, for instance, putting forward a verificationist criterion of meaning.
Black (p. 377): “It will be noticed, of course, that the method pursued in the Tractatus is not the ‘correct’ one.”