by This quote from Eliezer Yudkowsky puts pretty much puts all doubts I had regarding the Repugnant Conclusion with this little bit of his essay "The Lifespan Dilemma"
(If you need a refresher on what the allegedly Repugnant Conclusion is, see the relevant Stanford Encyclopedia of Philosophy article.)
My own analysis of the Repugnant Conclusion is that its apparent force comes from equivocating between senses of barely worth living. In order to voluntarily create a new person, what we need is a life that is worth celebrating or worth birthing, one that contains more good than ill and more happiness than sorrow - otherwise we should reject the step where we choose to birth that person. Once someone is alive, on the other hand, we're obliged to take care of them in a way that we wouldn't be obliged to create them in the first place - and they may choose not to commit suicide, even if their life contains more sorrow than happiness. If we would be saddened to hear the news that such a person existed, we shouldn't kill them, but we should not voluntarily create such a person in an otherwise happy world. So each time we voluntarily add another person to Parfit's world, we have a little celebration and say with honest joy "Whoopee!", not, "Damn, now it's too late to uncreate them."
And then the rest of the Repugnant Conclusion - that it's better to have a billion lives slightly worth celebrating, than a million lives very worth celebrating - is just "repugnant" because of standard scope insensitivity. The brain fails to multiply a billion small birth celebrations to end up with a larger total celebration of life than a million big celebrations.
(If you need a refresher on what the allegedly Repugnant Conclusion is, see the relevant Stanford Encyclopedia of Philosophy article.)
