Even the best of all possible lives consists of a mixture of pleasure and pain. Had the pleasure been forgone—that is, had the life never been created—no one would have been the worse for it. But the world is worse off because of the suffering brought needlessly into it. One of the implications of my argument is that a life filled with good and containing only the most minute quantity of bad—a life of utter bliss adulterated only by the pain of a single pin-prick—is worse than no life at all,” Benatar writes.
Suppose you’re thirty. Selfishly speaking, you conclude that the most pleasant number of children to have during your thirties is one. During your forties, your optimal number of kids will rise to two—you’ll have more free time as your kids assert their independence. By the time you’re in your fifties, all your kids will be busy with their own lives. At this stage, wouldn’t it be nice to have four kids who periodically drop by? Finally, once you pass sixty and prepare to retire, you’ll have ample free time to spend with your grandchildren. Five kids would be a good insurance policy against grandchildlessness.