Scott Alexander recently posted a link to this article which was very interesting. After reading it, the difference between postmodernism and LW rationality seems very large. It doesn't directly address your point, but you may find it interesting.
Separately, I think that you are exaggerating the tendencies LW shares with postmodernism. While LessWrongers love going meta (and they seem to love it even more in person than on the site), what you actually see in discussions here and on rationality blogs is requests to go in either the meta or object-level directions as required by the interlocutor. CFAR specifically has lessons on going toward object-level. Comparing the jargon of postmodernism and LessWrong is not really an equal comparison either. Postmodernism is oftentimes intentionally obscure, and sometimes redefines words to very surprising meanings (see the above linked article), while on LessWrong people seem to go to some pains to coin new language only when old language is insufficient, and explicitly consider what appropriate names would be (the major exception to this is perhaps language coined during the time of the sequences that is still widely used). LW doesn't have a strong need to justify itself to outsiders, but members of Less Wrong seem to mostly have explicit desire to spread rationality, so there is some need. Postmodernism, on the other hand, seems like mostly an insiders-only club. Compare Spreading Postmodernism with Spreading Rationality.
on LessWrong people seem to go to some pains to coin new language only when old language is insufficient
Are you sure? One of the biggest problems with LW is inventing jargon for philosophical ideas that have had names for a couple of thousand years. This is problematic if the interested reader wants to learn more.
The following two paragraphs got me thinking some rather uncomfortable thoughts about our community's insularity:
- Chip Morningstar, "How to Deconstruct Almost Anything: My Postmodern Adventure"
The LW/MIRI/CFAR memeplex shares some important features with postmodernism, namely the strong tendency to go meta, a large amount of jargon that is often impenetrable to outsiders and the lack of an immediate need to justify itself to them. This combination takes away the selective pressure that stops most groups from going totally crazy. As far as I can tell, we have not fallen into this trap, but since people tend to fail to notice when their in-group has gone crazy, this is at best weak evidence that we haven't; furthermore, even assuming that we are in fact perfectly sane now, it will still take effort to maintain that state.
Based on the paragraphs quoted above, having to use our ideas to produce something that outsiders would value, or at least explain them in ways that intelligent outsiders can understand well enough to criticize would create this sort of pressure. Has anyone here tried to do either of these to a significant degree? If so, how, and how successfully?
What other approaches can we take to check (and defend) our collective sanity?