[This post discusses the Derek Parfit paper ‘Equality or Priority?’, and honestly, you would benefit more from reading that paper than this post if you want to really get into the weeds of the priority view. That being said, the paper is fairly long, and perhaps slightly unfriendly to those not engaged with much political philosophy, so read on if you don’t have the time to digest a ~40 page political philosophy paper. Further, this post assumes you are somewhat familiar with
sounds like maximising sum(log(utility)) - seems entirely reasonable. Really this is just utlitarianism with a different utility function though, no?
Nice writeup! Though I think the phrase "priority to the worst off" can lead astray, or at least confuse between prioritarianism and some ideas in Rawls' difference principle and the adjacent idea of leximin. I think a better oneliner to catch the core of prioritarianism as "the lower someone's present wellbeing is the better it is to make it go up one unit of wellbeing".
Worth mentioning also that some of the intuitions that prioritarians often draw on in discussions with utilitarians can also be appealed to by other alternative views. One could say that prioritarianism is only one among several options among the family of views called suffering focused ethics. Magnus Vinding's book is the best overview there https://magnusvinding.com/2020/05/31/suffering-focused-ethics-defense-and-implications/
fyi, in the first half of this post I set out an objection to the priority view, and suggest an alternative form of utilitarianism that can secure the same verdicts without the theoretical cost:
Are you always prioritizing the worse off, or just applying different weights to them? For instance, if the happy friend got 1000 utils and the depressed friend got 1 util, would you still go for the depressed one? If not, if you are just applying different weights to them, then you don't deal with the utility monster objection. You just have to increase the gains of the monster, potentially making the monster exponentially happier, as in the more utility they have, the more utility they gain from actions.
but they are both maximising the utility gain: one the absolute value (i.e. 10 over 5), the other the relative value (i.e. 5/z1 over 10/z2, where 2 * z1 < z2)
"Nagel’s view is this: if you say that you would live in the city for the sake of your disabled son, despite it being the case that moving to the city creates more utility in total, you are not a utilitarian (at least in all circumstances), but rather an egalitarian."
Did you mean to write that moving to the suburbs creates more utility in total?
Unless these thought experiments consider the circumstances of the individual making the decision, it doesn’t actually reflect anything useful. One might select “living in the city” because going to the hospital so often is a major pain in the posterior, which living in the suburbs would only exacerbate. Any gain or loss regarding utility/etc where the children are concerned is incidental, and drawing conclusions about egalitarianism in that case is a serious error.