The Tractatus was an important influence on the philosophical position developed by the Vienna circle, which was also influence by sessions held by some members of the circle with Wittgenstein.
Some Tractarian positions were not adopted, e.g.:
What was embraced included:
Logical positivism collapsed for the following reasons:
Carnap, as indicated in his principle of tolerance was pluralistic about the reductive base.
Can't see why this should be the case for a physicalist reductionism. This does abolish irreducibly mental language, but reduction to the physical is not at all the same as reduction to behaviour (i.e. a mind/brain identity thesis need not entail any kind of behaviourism),
Though there abandonment leaves may other aspects of logical positivism intact.
A weak form of conventionalism is to state that necessary truths are true solely in virtue of the meaning of the language in which they are expressed. If ``solely in virtue of'' is simply intended here to mean ``without need of any empirical evidence'' then I myself continue to defend this hypothesis. However, if conventionalism is interpreted as entailing that the laws of logic can be explained as conventional, so that ``solely in virtue of'' is intended to mean ``without making use of any logic'' then there is a problem in the necessary machinery for applying the conventions. If we consider formal languages then Frege's formula ``Mathematics = Logic + definitions'' is helpful, in that it suggests that analytic statements are reducible to logical statements (provided one has a logic in which definitions are possible, i.e. which provides an adequate abstract ontology). A conventionalist even of the weak variety would still want to say that the truths of the pure logic were also true as a result of the choices we made in formulating the language, but deny that any account of the conventions can provide an absolute terminus in the infinite regress which can be expected when we attempt tne anything.
But how much did this matter? Were they actually trying to do this? Were they not concerned with scientific language, and urging the use of formal notations in preference to natural languages?