Utilitarianism is far and away the most attractive and popular moral principle ever put forward by a serious philosopher, but it gets very little respect from most in the philosophical profession. Leaving aside the rather more sophisticated objections of Parfit and others [Parfit, by the way, fifty years ago or so submitted to me at Columbia a one hundred and ten page paper defending act utilitarianism in a course he was not even taking for credit -- there were giants in the earth in those days, as the Good Book says], there are several seemingly crippling objections to the form of utilitarianism advanced by Jeremy Bentham in his Introduction to Principles of Morals and Legislation .
Bentham's formula, which as everyone knows is usually referred to as the Greatest Happiness Principle, calls upon us to choose that act or law which promises to produce the greatest happiness for the greatest number of persons, each one to count for one. If the principle is construed in what seems the natural way as meaning that we must try to make each person as happy as we can, then it is in general impossible to comply with, because it commands us to maximize each person's utility function simultaneously, and save in special circumstances, it is impossible to maximize two or more functions at once. If, on the other hand, we understand the principle as calling on us to maximize the total happiness in society, each person's happiness or unhappiness being given the same weight, than there are all manner of objections that appear upon consideration to be absolutely crushing. Even if we ignore the really hairy problems introduced by taking into account the happiness of future generations [problems for whose elaboration Parfit is quite famous], it seems manifestly wrong to impose pain on a few innocent folks in order to reap increased pleasure for the many -- just the sort of consideration that led John Rawls to advance his Theory of Justice.
Because philosophers have spent so much time exposing the theoretical weaknesses of utilitarianism, it is difficult for us today to recall just how revolutionary the Greatest Happiness Principle was, and was intended to be, when Bentham first articulated it. The truly radical part of the principle was not the identification of pleasure with the good -- by the late eighteenth century, there was a hedonist tradition in ethical theory going back at least two thousand years. No, what really upset the applecart was the specification, "each one to count for one." The problem, you see, was that the principle gave the same weight to the pains and pleasures of peasants as it gave to those of aristocrats. To be sure, one could argue, as many did, that because aristocrats had such refined sensibilities they were likely to suffer excruciating pain from bodily insults that rough peasants would scarcely notice [a theory immortalized in the Hans Christian Andersen story, The Princess and the Pea.] But there were so many peasants and so few aristocrats! Even the dullest dukes and duchesses could see that once you began adding up pleasures and pains à la Bentham, the interests of the masses were going to outweigh those of the classes. Indeed, Bentham's principle, as he quite well intended, constituted a very powerful argument for democratic government resting on universal suffrage. [Strictly speaking, to get to that conclusion required adding the lemma that each person is the best judge of his or her own pain and pleasure, an assumption with which Bentham was comfortable but that proved a bridge too far for his godson John Stuart Mill.]
But the real problem, which was clearly understood by a great many bright economists, was that utilitarianism seemed ineluctably to lead us to an endorsement of a far-reaching redistribution of income. After the so-called marginalist triple revolution of the 1870's, economists were prone to claim that individuals have declining marginal utility for wealth. This means, roughly, that the richer you are, the less pleasure you get from each additional dollar you can lay your hands on. This is certainly plausible [although you can consult a classical article by Milton Friedman and Leonard Savage for some objections and quibbles], but the principle of declining marginal utility was really embraced because it made all the math so lovely. The problem was that if you take a dollar away from a Ritchie Rich and give it to a poor minimum wage worker, the pain suffered by the toff because of the loss will be less than the pleasure gained by the working stiff, and that will increase the total happiness of society. Well, that was clearly an unacceptable inference! Modern economics did not come into existence to justify Robin Hood policies of stealing from the rich and giving to the poor.
As it has so often in the past, Philosophy came to the rescue, this time by discovering the problem of Other Minds. Each of us, Philosophy decided, John Donne to the contrary notwithstanding, is an island, incapable of establishing more than the most indirect communication with the other islands in the sea of humanity. Whew! Close call! If I cannot ever really know what is going on in your mind, then I cannot measure your pains and pleasures against my own, establish a common unit of measurement, and add them all up. Capitalism was saved, and economists could go back to elaborating elegant mathematical structures confident that in so doing they would not be burning the house down. Thus sprang up indifference curves, production possibility frontiers, general equilibria, and all the other gems of the modern Economics profession. Here is the classic statement of this saving argument as stated in that old classic, An Essay on The Nature and Significance of Economic Science by Lionel Lord Robbins in 1932:
"There is no way of comparing the satisfactions of different people. ... Hence the extension of the Law of Diminishing Marginal utility, postulated in the propositions we are examining, is illegitimate. ...The conception of diminishing relative utility (the convexity downwards of the indifference curve) does not justify the inference that transferences from the rich to the poor will increase total satisfaction." [selected from pages 140-141 of The Essay.]
But if this seemingly sensible inference is illegitimate, what are we left with? Well, to lapse into tech talk, we are left with unanimity partial orderings, which are said to exhibit, after Vilfredo Pareto, Pareto Optimality. In brief, any change that makes at least someone better off [higher on his or her Indifference Curve] without making anyone worse off, is clearly preferable [assuming no envy, which is why Rawls sticks in that odd caveat.]
Apologists for capitalism, which is to say professional economists, showing a positive genius for propaganda, call this state of affairs "efficient." I mean, who on earth could be against efficiency, especially in America? So the present distribution of wealth and income is efficient, so long as taking a dollar away from a billionaire and giving it to a poor man makes the billionaire even the slightest bit less happy. Unless, of course, the transfer has the all-round happy effect of somehow increasing the total output of the society so that the billionaire can be given his dollar back [or, more likely, a million dollars back] while also leaving enough to give the poor man an extra crust of bread, which will, ex hypothesi, move him a tad up his indifference curve. [They give Nobel Prizes for this stuff. I think astrologers should complain.]
Which brings me back to Bentham and the reason why I started this extended rant. For all its manifest flaws, utilitarianism is the only ethical theory that actually tells me how to think about one of the hardest questions in political theory and public life: How can I judge which of the innumerable outrages that assault me deserve my closest attention? How can I tell whether a complex policy pursued in a complex world is making things better or worse? Was a homophobic America that treated African-Americans and women as second-class citizens a worse or a better place than an America in which the condition of African-Americans, women, and the LGBT community has dramatically improved, but in which income inequality has soared, the state routinely tortures its political prisoners, and labor unions are dying? Save by means of some sort of "felicific calculus" [to use the old-fashioned term], I do not know how to begin thinking about this question.
So let's hear it for old Jeremy Bentham. A wax replica of his head may sit atop his skeleton stuffed with hay and clad in his own clothes, but his heart was in the right place.