If I am a momentary conscious self, and might have (numerically) the same experience as I do now even if I were not causally connected to anything more remotely past or future than the before and after internal to my momentary experience […], then it seems that my continuant personal identity should not be of all that much special interest to me-now. For if the way that I am a continuant is by being a collection of, say, segments of continuing physical processes coming together into integrated systems of neural events at one moment only to come apart the next, why should I identify with the future of some of these causal processes rather than with others? Why not care equally about other momentary consciousnesses that I can causally affect, rather than just about that which bears my name? Why not about those that carry the effects of my deeds, or of my social interaction, equally? None of these will be the same momentary consciousness as I this moment am. All will be tied to my present consciousness by causal connections.
These considerations seem plausible to me. But, of course, they cannot really be used to foster the moral virtue of benevolence—which, like all of morality, essentially concerns our relations to persons as such. If this scene of thought undermines egoism and the egocentric fears (such as, perhaps especially, the fear of death), it might seem equally to undermine morality, too—by weakening the grip that our biologically- and socially based perception and attitudes toward persons as such have. For it seems to be here that morality finds its natural ground—on which the existence of moral facts and motivation, and the application of the distinctive normative force of morality (irreducible to that of seeking pleasure or any other form of welfare or good) depends. But philosophical hedonism, while perhaps undermining morality and self-interest together in this way by suggesting the momentary view, could also provide some justification for self-interest and morality in those moments in which we wonder how it all matters, at a fundamental level, by showing a deeper ground and point to human living—a ground in the momentary experience of pleasure (no matter whose), a ground beyond self interest and morality that lies deeper in the nature of things than does our perception of persons or of prudential and moral norms.
Leonard Katz, Hedonism as Metaphysics of Mind and Value, Ph.D. dissertation, Princeton University, 1986, pp. 177-179