Two popular arguments for utilitarianism are the following:
The egg argument: the egg is a short story describing a tale of someone who dies and discovers that they will live the lives of everyone in the world. The neighbor who they were rude to, their spouse, the dog that they provided shelter to were all different versions of them. They will live every life in the universe. But it seems that acting rationally in such a world suffices for one to act morally—if you regard everyone else as if they are just as important as you, treating their interests as just as significant as your own, that seems to exhaust morality. But when one counts everyone’s interests equally and acts as they would if there was one superbeing who lived everyone’s life and was optimizing for being well-off, they act as a utilitarian, for they act to maximize well-being.
The veil of ignorance argument: imagine if you made decisions from behind a veil of ignorance, unsure if you were the beneficiary of an action or its victim. From behind the veil of ignorance, you’d value everyone’s interests equally, because you could be any of them. It can be shown that if we imagine everyone being behind the veil of ignorance and acting based on a few minimal axioms of rationality—such as that some action is better than another if it’s better for everyone in expectation and that one’s evaluation of states of affairs should be transitive and complete—that one would be a utilitarian.
I think these arguments are pretty convincing. Once you take into account everyone’s interests and count everyone’s interests equally—valuing far-away people just as much as you would if they were nearer—it seems that that exhausts morality. Extra moral laws seem like arbitrary strictures on the pursuit of value—if you wouldn’t follow some moral rule if you counted everyone equally, then you shouldn’t follow it at all. The conception according to which morality boils down to applying the principle of rational choice for an individual to sentient beings as a whole is a deeply appealing one.
This basic intuition is what draws many people to utilitarianism. But crucially, I think that there are two more ways we can utilize such cases as an argument. The first is the following:
An action is right if and only if it would be taken by one who was fully rational and impartial.
One behind the veil of ignorance or in the egg scenario who was given full rationality would be fully rational and impartial.
Therefore, an action is right if it would be taken by one who was in the veil of ignorance or egg scenario and was fully rational.
One who was fully rational in the egg scenario or veil of ignorance scenario would take only those actions prescribed by utilitarianism.
So an action is right only if it is prescribed by utilitarianism.
Each premise seems very plausible. The only premise anyone would be inclined to reject would be two perhaps, based on claims that one has special obligations to their friends and family—I’ve argued against that elsewhere. So every premise of this argument is plausible, and the conclusion entails the rightness of utilitarianism.
Of course, one could accept that morality is about more than just impartiality + rationality. But this seems to be strictly inferior to the utilitarian account. Why think that those who are fully rational and impartial act wrongly? It’s hard to imagine a case of acting wrongly while correctly identifying what is of value (via complete rationality) and valuing everyone equally (being impartial). The utilitarian conception seems much more attractive.
But I think that the most forceful version of the argument doesn’t have to do with the notion that this exhausts morality but instead with the notion that what one would do in the egg or behind the veil of ignorance shouldn’t conflict with morality. Imagine that at the end of your life you discover that you are in the egg scenario. Should you regret acting rightly? It seems intuitively that the answer is no. You should regret acting selfishly, because doing so will be bad for you, but it seems you should not regret acting in ways that you had every reason to believe were right. But the non-utilitarian must deny this—every action you took that conflicted with utilitarianism is one that you should regret, for it will be bad for you and good for no one else; after all, you are the only one who exists. Not pushing the person in the Bridge case, for instance, will be something deeply regrettable.
Similarly, imagine that you unexpectedly find yourself in a veil of ignorance scenario. You take an action, but after doing it, you unexpectedly find that you will not remain the person who took the action, but instead will be a random other person. When you are in limbo, about to become a specific person, you should not to think “oh shucks, if only I hadn’t acted rightly—now everyone is worse off in expectation.” Right action shouldn’t be the type of thing you regret when you become impartial—by being behind the veil of ignorance or in the egg scenario—but only utilitarianism can explain that intuition.
Once we have this thought experiment in hand, it helps to diffuse many of the objections to utilitarianism. For instance, in the organ harvesting scenario, once you realize that:
our intuitions about the scenario have been biased by lots of unreliable factors;
you’d approve of organ harvesting if you were impartial and rational or if you counted everyone’s interests equally;
the intuition about the wrongness of organ harvesting starts to go away. What we’d do if we were rational and impartial seems to be what fundamentally matters—and the rest seems to be little more than our brain over-extrapolating the general trend that murder is bad. Once you realize that you’d approve of organ harvesting from behind the veil of ignorance—and if you lived everyone’s life, as in the egg scenario, you’d be glad you killed the person to harvest their organs—the intuition fades.
The common criticism of utilitarianism is that it’s moral theorizing run amuck—the utilitarian maxim sounds good until you realize its crazy implications and then sensible people abandon it. Unfortunately, utilitarians get too wedded to the principle, and refuse to give it up even when it produces crazy implications. But I don’t think this is true at all! When you actually internalize the intuition about the veil of ignorance, it’s not that it entails lots of crazy things, it’s that enables you to grasp why crazy-sounding things are not crazy at all, and in fact right.
When you realize that refusing to harvest the organs in the organ harvesting scenario or push the man off the bridge in the bridge case involves putting some pious conception of rightness over the lives of four additional people—people who have value, who will now never live out their lives because your conception of rightness said they had to die—and that you’d never take the action if you were impartial—that every person from behind the veil of ignorance would oppose the action—it becomes easy to see that the intuitive revulsion in the organ harvesting case is unreasonable. The lives of four extra people are fundamentally more important than not getting our hands dirty, and any moral view that doesn’t recognize that fact is deeply impoverished.
"1. An action is right if and only if it would be taken by one who was fully rational and impartial.
2. One behind the veil of ignorance or in the egg scenario who was given full rationality would be fully rational and impartial.
3. Therefore, an action is right if it would be taken by one who was in the veil of ignorance or egg scenario and was fully rational.
4. One who was fully rational in the egg scenario or veil of ignorance scenario would take only those actions prescribed by utilitarianism.
5. So an action is right only if it is prescribed by utilitarianism."
There's a lot of merit to this argument, but let's quickly break down some forms of counterattack you haven't mentioned:
(1.) A lot of people object to 1 on the basis that we should be partial towards our nearest and dearest, towards those who are entangled in our lives in various ways, towards those we owe gratitude, towards our constitute commitments etc. etc. Other people will argue that we should be biased towards acting on our desires because they are our desires.
(4) Is considered dicey, perhaps unfairly, because of Rawl's classical and somewhat bizarre claim that you should adopt Maxmin behind the veil of ignorance.
(5). Okay I have a somewhat technical objection here. In the argument that you establish that those in the egg/Veil of Ignorance condition would be rational and impartial, that they would be utilitarian, that they would be right and that rationality and impartiality are necessary and sufficient conditions for goodness. However you never actually rule out that there aren't alternative ways of being rational and impartial which aren't utilitarian but which nevertheless count as Rational and impartial- ways of being rational and impartial that apply when one is not behind the veil. Maybe outside the Egg & Veil of ignorance scenarios, there are other ways of acting that count as rational and impartial, and are therefore permissible by your 1. Is it plausible that there are such things? Hard to say.
I've often thought that the best justification for Utilitarianism came from Kant's Golden Rule, as it logically extends into the objective moral arbitrator concept.