One problem in hedonistic utilitarianism is how to treat mental pain – or distress, as I would prefer to call it. The fact that some actions might cause distress to people sometimes leads people to make dubious interpretations of what hedonistic policies might look like. For example, if it is the case that the mere thought that homosexual intercourse is taking place causes some mental distress for a substantial amount of people, then wouldn’t the hedonist have to say that homosexual intercourse must be forbidden? (This may not be the most interesting example to bring forward, since most people who argue against homosexuality do not do it on utilitarian grounds, but anyway…)
To answer this we must firstly put the distress of those who are being denied the opportunity to engage in sexual activities in the balance. Even so, it may still be the case that the distress of a lot of straight people counterweighs the distress that comes from a relatively small minority of people being sexually frustrated. Would the hedonist have to concede that in this case, the ban on homosexual intercourse is still a good policy?
I would say no, since it is still the case that many (probably most) of those who feel such grave distress at the mere thought of homosexual intercourse taking place feel this distress merely because they have previously formed (or have been taught) the preference that homosexuality is wrong. On the other hand, most people who see absolutely nothing immoral with homosexuality do not feel very much mental distress when imagining homosexual activities, or at least not so much distress that they feel warranted in complaining about it.
In other words, if grave cases of mental distress are caused by certain preferences (or ideas), and if the distress would go away if the preference were to go away, then it seems unreasonable to count this distress in the summation of pleasures and pains. I might have a preference not to be tortured, but the pain of the torture does not go away if I somehow managed to talk myself out of this preference. I might have a preference for eating ice cream, but the pleasure of eating ice cream would (in most cases) not go away if I got rid of this preference (otherwise, imagine how easy it would be to lose weight, stop smoking, etc.).
But the pain of thinking about about homosexuality will (at least in most cases) be considerably mitigated if the preference against it disappears. We might say the same thing about the pains and pleasures pertaining to revenge. If we get the (rather primitive) idea out of our heads that all wrongs must be revenged by inflictions of pain to the offender that supersedes the pain inflicted to the victim, then we would probably not feel so much pain when someone who has done us wrong is not getting the punishment he or she “deserves”.
It should also be added that we are often fooled by our preferential pleasures when it comes to planning our own lives. We often think that we will be happier if we only take this or that journey, buy new clothes or furniture, pursue a certain career, win another medal, have another child etc. etc. Often we turn out to be mistaken. Or preferences do not always increase our pleasure (or reduce our pain). Of course, it may be the case that we get a certain amount of joy (mental pleasure) from the mere act of planning these future events, and it would seem strange to discount this joy just because it is built out of as yet imaginary things. If it all stopped at planning then no harm would be done; but if we are fooled by these preferential joys we will eventually try to make the things themselves happen, and often find out that we are no happier than before. We would, in other words, find out ex post facto that we could have used our energy on other things that would, perhaps, have a greater change of increasing our pleasure.