This topic is vague and open-ended.  I'm leaving it that way deliberately.  Perhaps some interesting, better defined topics will grow out of it.  Or perhaps it's too far afield from the concept of less wrong cognition to be of interest here.  So I view this topic as exploratory rather than as an attempt to solve a specific problem.

What useful purposes does religion serve?  Are any of these purposes non-supernaturalistic in nature?  What is success for a religion and what elements of a religion tend to cause it to become successful?   How would you design a "rational religion", if such an entity is possible?  How and why would a religion with that design become successful and serve a useful purpose?  What are the relationships between aspects of a religion, and outcomes involving that religion?  For example, Catholicism discourages birth control.  Lack of birth control encourages higher birthrates among Catholics.  This encourages there to be a larger number of Catholics in the next generation than would otherwise be the case,  Surely there are other relationships like this?  How do aspects of religion cause them to evolve differently over time?

This was going to be a reply in a discussion between ChristianKl and MattG in another thread about conlangs, but their discussion seemed to have enough significance, independent of the original topic, to deserve a thread of its own.  If I'm doing this correctly (this sentence is an after-the-fact update), then you should be able to link to the original comments that inspired this thread here: http://lesswrong.com/r/discussion/lw/n0h/linguistic_mechanisms_for_less_wrong_cognition/cxb2

Is a lack of ambiguity necessary for clear thinking?  Are there times when it's better to be ambiguous?  This came up in the context of the extent to which a conlang should discourage ambiguity, as a means of encouraging cognitive correctness by its users.  It seems to me that something is being taken for granted here, that ambiguity is necessarily an impediment to clear thinking.  And I certainly agree that it can be.  But if detail or specificity are the opposites of ambiguity, then surely maximal detail or specificity is undesirable when the extra information isn't relevant, so that a conlang would benefit from not requiring users to minimize ambiguity.

Moving away from the concept of conlangs, this opens up some interesting (at least to me) questions.  Exactly what does "ambiguity" mean?  Is there, for each speech act, an optimal level of ambiguity, and how much can be gained by achieving it?  Are there reasons why a certain, minimal degree of ambiguity might be desirable beyond avoiding irrelevant information?

I'm working on a conlang (constructed language) and would like some input from the Less Wrong community.  One of the goals is to investigate the old Sapir-Whorf hypothesis regarding language affecting cognition.  Does anyone here have any ideas regarding linguistic mechanisms that would encourage more rational thinking, apart from those that are present in the oft-discussed conlangs e-prime, loglan, and its offshoot lojban?  Or perhaps mechanisms that are used in one of those conlangs, but might be buried too deeply for a person such as myself, who only has superficial knowledge about them, to have recognized?  Any input is welcomed, from other conlangs to crazy ideas.