According to JS Mill, “In the golden rule of Jesus of Nazareth, we read the complete spirit of the ethics of utility. To do as one would be done by, and to love one’s neighbour as oneself, constitute the ideal perfection of utilitarian morality.”
Mill was an avowed atheist. Why did he draw such a close connection between his own utilitarianism and the ethics of original Christianity?
Trivially, we all tend to maximise the satisfaction of our own preferences when we act. By choosing to do X rather than Y, we reveal that we prefer doing X to doing Y. To prefer X to Y is simply to “go for” X rather than Y.
Normally, we would like other people to maximise the satisfaction of our preferences when they act as well, because that would help us to achieve our goals, which we are already striving to achieve through our own actions. To have additional help in doing so — to have them throw their weight behind our own attempts to satisfy our own preferences as much as possible — is how we “would be done by” them.
So if we were to do to them as we would be done by them, we would try to satisfy their preferences as much as possible. And of course the same thing can be said symmetrically for them. So if the “golden rule” of doing as we would be done by were followed by everyone, everyone would be striving to satisfy preferences in general as much as possible.
If we understand interests as the satisfaction of preferences, as I think we should, it means that all interests count, no matter whose interests they may be. To be more precise: since preferences can be strong or weak, interests should be given due consideration — which means they should be respected for the actual strength of the preference they correspond to. When thinking about animals of the same species such as humans, “due” consideration nearly always means equal consideration.
If morality were the only motivating factor in human life, and everyone accepted preference utilitarianism, then everyone would respect preferences in general. This would necessarily involve a huge amount of compromise, as each individual’s preferences inevitably come into conflict other individuals’ preferences. But as an ideal, preferences would be respected as much as possible regardless of whose preferences they were.
Of course in reality the effects of our actions are limited. I can’t affect people who live a very long way away from me (although this changes as time passes). And our knowledge is limited: I cannot predict what effect my actions will have on people living in the distant future. But I can affect people who live reasonably close to me (in causal terms) yet who can’t be counted as either family or friends. At one time, these people would literally have been my “neighbours”. The preference utilitarian moral ideal is to respect their preferences as much as my loved ones’ preferences and my own preferences. The ideaI would be to “love my neighbour as myself”.
So much for what Mill called the “ideal perfection of utilitarian morality”. It’s an ideal because no one could hope to fully achieve it in action, and there are other important values that complete with moral value — such as beauty, truth, clarity, love, loyalty, eroticism, profit, and fun (which are just the first few I can think of).
Yet preference utilitarianism is not what is normally called “idealism” in the political sense. No perfect state needs to be achieved for utilitarian morality to “work”, as Marxism might need the total embrace of communism to “work”, or libertarianism might need a perfectly free market to “work”. In the imperfect world as it really is right now, utilitarians strive to behave morally by satisfying preferences as best they can. Where the strongest preferences are at stake, moral value can become the principal guiding light of action. Like the demands of original Christianity, the demands of utilitarianism can never be perfectly met — but we can strive to approximate meeting them, the closer the better. To my mind, that is a humane and realistic thing to strive for.