BLUF: If total utilitarianism’s obligation to create new beings seems non-intuitive, think of increased numbers of beings as increased duration of subjective experience. We are allowed to redefine population as duration because subjective experience is fundamentally impersonal and based on physics, where there is no room for personhood.
Total hedonic utilitarianism says that we ought to consider both the desirability of any subjective experience as well as the number of subjective experiences in determining moral action. Level of happiness is a pretty intuitive aspect of total utilitarianism. All things considered, we want any creature to have a more desirable subjective experience, everything else the same.
I empathize that it less intuitive that we ought to value additional beings with net-positive subjective experiences. “Are we really obligated to make additional happy beings?” is a fair question. This is captured in Derek Parfit’s repugnant conclusion, “For any possible population of at least ten billion people, all with a very high quality of life, there must be some much larger imaginable population whose existence, if other things are equal, would be better even though its members have lives that are barely worth living”.
I think that a more intuitive, but equally fair way to consider the moral intuitiveness of our obligation to have additional beings given a fixed average quality of positive subjective experience is that we can represent the number of beings via duration of experience. More beings alive at any given moment can be thought of as a greater duration of subjective experience of a single being.
I think duration is pretty intuitive to ethically desire. All things the same, we prefer a desirable subjective experience to continue.
We are allowed to redefine population as duration because subjective experience is fundamentally impersonal and based on physics (where there is no room for personhood).