This one is important because Rawls's device of "the original position" is one clever way to make utilitarianism mathematically respectable, in that it permits interpersonal comparison of utilities.
What !?
I would like to thank you for your expression of incredulity. It forced me to look at the question a little more closely, and led me to this excellent paper by Binmore. If I had read it first, I would not have been so complimentary about Rawls. I had forgotten just how different Rawls's 'Veil of Ignorance' is from Harsanyi's. And it is Harsanyi's version that deserves our respect, not Rawls's. Nevertheless, I think I was technically correct. Rawls is mathematically respectable, however deficient he is on more realistic grounds.
There are several issue...
Are there any areas of study that you feel are underrepresented here, and would be interesting and useful to lesswrongers?
I feel some topics are getting old (Omega, drama about moderation policy, a newcomer telling us our lack of admiration for his ideas is proof of groupthink, Friendly AI, Cryonics, Epistemic vs. Instrumental Rationality, lamenting how we're a bunch of self-centered nerds, etc. ...), and with a bit of luck, we might have some lurkers that are knowledgeable about interesting areas, and didn't think they could contribute.
Please stick to one topic per comment, so that highly-upvoted topics stand out more clearly.