@Olivier5,
The most interesting aspect of Wittgenstein, IMO, is that he rejected his own acclaimed
Tractatus. He seems to have spotted the emperor's new clothes (of logical positivism) himself. Quite separately to W's
language game analysis at the micro-level of discourse ,Thomas Kuhn seems to have developed the macro-idea of shifting paradigms in whole scientific communities. And separately to both of these, Piaget's "genetic epistemology" (assimilation/accommodation) had postulated the idea of dynamic cognitive "schemata" in psychological development in which what we call "knowledge" is a function of the progressive dynamic interaction between cognitive states and their segmentation of "the world". (NB Piaget aimed to
account for "logical thought" and could not assume it in his analysis !)
Thus for me, constructivist approaches are justified by at least three separate domains of analysis (individual, social and cultural) originating from different sources. Quite frankly, those who might dismiss such approaches in favour of some version of traditional "logical analysis", have not understood them.