This originally formed part of a longer paper on ethics and desire. On revising the paper, I found that it didn't fit very well with the rest, but I liked it too much to throw it away, so here it is.
To simplify the relation between desire and morality, and between personal and moral good, we can imagine a world of only two people; let us call them Adam and Eve, for the sake of tradition. This gives us two types of personal good: good for Adam and good for Eve. What is good for Adam (or Eve) is what tends to realise his or her desires in general, and, where desires conflict, realises the desires that are stronger in the long-term. A benevolent and omniscient observer—let's call him Snake out of perversity—could therefore draw up two plans of action, one which is good for Adam and one which is good for Eve. However, at this point, Snake must choose sides, since obviously these goods are not always compatible. It is here that Snake must evolve into a moral being, since he must find a way to choose between good-for-Adam and good-for-Eve in order to produce a general good (even though we have not really decided what the general good might involve yet).
One method which Snake may choose is to treat Adam and Eve as essentially one person, bundling all their desires together, then applying a kind of calculus of desire, i.e. desires which are stronger in the long run win out over weaker or more transient desires. For example, if there is only one apple left on a tree, and both Adam and Eve want it, but Eve wants it more, then Snake will recommend that Eve eat the apple (not that apple, of course). However, this is complicated by the fact that Adam and Eve are not really the same person, and Adam will now feel hard done by. Adam now has a moral sense, in that he perceives that since there is no reason why Eve's desires should take precedence over his, a situation in which Eve's desires are realised and his are not is somehow wrong; it frustrates not only his basic desires, but also his values (i.e. his opinions about which desires should be realised). Snake would have to remember this, and, the next time a conflict occurs, give Adam's desire slightly higher priority, since now Adam not only has a weak desire to eat apples, but also a (possibly very strong) desire that Eve's desires should not always take precedence over his. Thus is justice born.
We may question, however, what this primordial sense of justice may be. Adam is obviously not appealing to some set of normative values, since these do not yet exist. What appears to be the case is that humans do not only assess the relative strength of their own desires, but, upon entering a relationship with another, assess the other person's desires as well. Since there is no pre-existing reason to assume that the other person's desires are more important than our own, we react negatively when another's desires are realised at the expense of our own, which may well be the origin of a sense of injustice.
While this may complicate the basic calculus, it does not yet invalidate it. In fact, we often do a similar thing when choosing between our own desires. We all contain different characters, sub-personalities, archetypes or whatever, and to act consistently in favour of the dominant one may create severe internal stress. A rational person will normally suppress desires which would sabotage their long-term goals, but will nevertheless indulge occasionally; for example, a person who is watching their weight will not normally eat chocolate cake, but may do so occasionally in order to avoid the stress that complete abstinence would bring.
There is, however, a crucial difference between our own regulation of our desires and the Adam and Eve situation, in that the latter requires an outside judge, while as individuals we can for the most part provide this function for ourselves, only applying for outside help when we are confused about what we want, or ignorant of the likely consequences of our actions; in such cases we may well ask a friend or specialist authority for advice. In our thought experiment we have been assuming that Snake is constantly advising Adam and Eve, and that they take this advice. However, let us assume that Snake begins to tire of his role and starts to wonder if there is some way that he can retire and leave our primordial couple to their own devices without their continually frustrating each other's desires (and thus, in all likelihood, their own).
Snake's plan will be facilitated greatly if Adam and Eve love each other, or at least give some weight to each other's desires. Since love is a complex phenomenon, let us simplify things by talking of empathic desire: the desire that another person realise their desires, whatever they may be. This is not the same as compatibility of desire; that is closer to rational self-interest, which may often lead to moral behaviour, but is a rather shaky foundation for it. To be more precise, rational self-interest is often a good practical basis for moral behaviour, but it is a weak philosophical basis, since it assumes a situation in which what is good for others will usually be good for oneself, and this is not always the case.
Returning to the fair division of apples, if Adam has empathic desire regarding Eve, he will be happy for Eve to eat most of the apples, and only object when he is really hungry; similarly, if Eve feels the same about Adam, she will sometimes insist that he eat the apple even when it is her “right” to do so. This is, in fact, the normal situation in any successful marriage or friendship. In these cases, empathic desire wins out over other desires; there is no need for complicated theories of altruism to explain this, unless we think it strange that people will often want others to have their own way. We can, if we choose, explain empathic desire, and its altruistic extremes, in psychological or biological terms (socialisation, species survival etc.) but it is not necessary to do so for philosophical purposes; we can simply accept empathic desire as an observable fact. This is what truly distinguishes negotiation of desire between individuals from an individual's regulation of her or his own desires, since one cannot really have empathic desire towards oneself (though we may simulate it through metaphor and fantasy, as in the currently popular practice of nurturing one's “inner child”).
While Snake may be pleased by this observation, he is still worried. Empathic desire may be fundamental to ethics, but its effects on the desire calculus can become horrendously complex. If both partners have excessive empathic desire, it can lead to a stalemate where each wants what the other wants and thus neither gets it (again this problem sometimes surfaces in marriages and other close relationships). More importantly, what happens where there is an extreme disparity of empathic desire? Ironically, if the disparity is total, there is no problem. We can imagine a system where Adam's only desire is to be Eve's slave, and Eve's desire is to have Adam obey her every whim; in this case both realise their desires, and under the terms we have described, there can be no objection to this arrangement, assuming that it is perfectly genuine and does not result from some subterfuge. An outside observer may object that Adam and Eve “ought not to” behave in this way, but it is hard to see on what criteria they could judge them, given that this is a closed universe.
Things become more problematic when there is a slight, but constant disparity in fulfilled desire. Let us imagine that both parties possess some empathic desire, but Eve has rather more. This would lead to her “giving” more and more, leading to a serious imbalance in the fulfillment of non-empathic desires. This is an all-too common situation in intimate relationships, and frequently leads to an explosive reversal of roles when the more empathic partner has had enough of what they see as the other's selfishness. In such cases, a formalisation of duties and benefits is usually necessary to prevent total collapse of the relationship.
Nevertheless, we can assume that if Adam and Eve have a normal amount of empathic desire, and their non-empathic desires are not too incompatible, they will get along well and not interfere too much with the fulfillment of each other's desires. What really worries Snake, in his role as moral arbiter, is that they will reproduce, begetting Cain, Abel and so on. With each extra subject in the equation, the desire calculus becomes harder to perform, and so it becomes necessary to formulate some rough and ready code of behaviour: a list of actions which on the whole will further or hinder the ability of people in general to realise their desires. At this point, Snake persuades Eve to eat the fruit which gives knowledge of good and evil; he is out of the garden, and so are they.
Robin Turner, 8/10/2001