There’s an old saw that states (in annoyingly sexist language, but put that aside here) that the child is father to the man. On at least one plausible metaphysical view about the nature of persons, I am the parent to all my future selves. If there is a sound argument for philanthropic antinatalism and if it is also the case that people have temporal parts, then is a pro tanto reason for committing suicide right now.
Consider: David Benatar’s argument that coming into existence is always a harm is driven by an asymmetry between pleasure and pain. It always bad for pain to be present and good for pain to be absent, but while it is always good for pleasure to be present, the absence of pleasure only if it there is someone for whom that absence would be a deprivation. All lives contain some pain, so coming into existence is always a harm.
I am writing on a pleasant Sunday afternoon. On Monday morning, if events take their natural course, I will have a future self that will suffer a little. He will have to get up to early, stuff himself onto a commuter train, and do a day’s work at a stressy, tedious job. Some things might go well for him, but these are not an advantage over never having had to suffer in the first place. Better never to get to Monday, perhaps. Further along in life, future desires will emerge in future selves. Many of these desires will be thwarted, leading to frustration. Better never to have those desires arise.
Thus we would seem to always have a pro tanto reason to commit suicide. Either that, or we have a reductio either of Benatar’s argument or the view that people have temporal parts.