would argue just as strongly for someone to be allowed to argue (reasonably) the other side ..." Is it fair to read that as asserting you would support any cogent, careful, and reasoned discussion, even if it were about a disadvantageous activity? "... given that each potentiality becomes an actuality and thus has an upper bound I don't follow that ..." Fair enough, that is reasonable. I can express it differently. You posed "why ought we value potentiality over actuality?" My response was "Because the potentiality, not having yet occurred, has no upper bound, while the actuality, being measurable, does." It is because the baby has a far greater range of possible futures than do you or I, being adults, the potential for that baby to add value, using some evaluation system, in one or more of those futures is greater than is yours or mine. To restate, your measured actuality(ies), whatever it or they may be, unless it is the best, has some probability P of being exceeded by a future measured actuality drawn from the current unrealized potentiality of the baby. Although your actuality may be greater than that baby's realized potentiality, and that baby's realized potentiality, and that baby's, et cetera, it is unreasonable to assume that your actuality will always be greater than the realized potentiality of all babies, as you will need to complete an infinite series to do so. "... you didn't engage with the thought experiment -- which would you save? The baby