“Parfit has always been preoccupied with how to think about our moral responsibilities toward future people. It seems to him the most important problem we have. Besides the issue of global warming, there is the issue of population. It would seem that if the earth were teeming with many billions of people, making everyone’s life worse, that would be bad. But what if the total sum of human happiness would be higher with many billions of people whose lives were barely worth living—higher, that is, than with a smaller population of well-off people? Wouldn’t the first situation be, in some moral sense, better? Parfit calls this the Repugnant Conclusion. It seems absurd, but, at least for a consequentialist, its logic is difficult to counter.”

— Larissa MacFarquhar, How to be Good (The New Yorker, September 5, 2011)