Outline and evaluate Mill's argument for the principle of Utility in Chapter 4 [of Utilitarianism].

In Chapter 4 of "Utilitarianism," Mill outlines his "proof" for the principle of utility. I use the word proof in inverted commas, because Mill himself believed that something as fundamental as the "ultimate end" of happiness cannot be directly proved; instead, he explains, evidence must be presented which a thoughtful and reasonable individual can evaluate as being consistent with the principle of utility.
The argument in which he presents this evidence takes the following form; firstly, he affirms the principle of hedonism, that pleasure, or happiness, is the only thing that is desirable for its own sake. Secondly, he asserts that each man desires what is good for him; as evidence he offers the controversial assumption that people desire only what is desirable, and therefore this can be characterised as being good. Thirdly, extending this, he makes the leap to the belief that the general happiness is good for all people. Finally, he shows that happiness is the only thing that is desired. All other things that are desired are desired because they themselves have become a part of the overall happiness.
In order to evaluate Mill's argument, each of these steps must be examined in turn, and the criticisms that have been levelled at Mill also examined closely.
The first point in Mill's argument, therefore, is the affirmation of the principle of hedonism that he first makes in the first chapter. This premise states that happiness is the only thing that is desirable in itself. There are two objections to this premise; the first takes pleasure to mean "lower" pleasures; however, Mill was at pains to distinguish between lower and higher pleasures, and there are surely many, many pleasures that do not involve mere bodily pleasure, e.g. the pleasure attached to power, or listening to an orchestra playing, or the study of philosophy, etc. So this objection could more accurately be described as a misunderstanding made in spite of the great lengths Mill went to in order to elevate utilitarianism above the criticisms of it being a doctrine for "swine-like self-gratification."
The second objection to this first premise is that people do not desire something only for the pleasure it yields; they must also desire the specific thing itself. This argument says that these objects are without doubt accompanied by pleasure, but it is the objects themselves, and not the pleasure alone which is desired. However, this argument loses its force if we suppose that someone says that they want pleasure and pleasure alone, without doing anything that we would ordinarily associate with inducing pleasure - for example, the person rejects drinking a glass of wine, going to a concert, or reading a book, and everything else. This is quite clearly nonsense, as it is impossible to have pleasure on its own, without being associated with something else. In other words, the pleasure contained in an act or object is inseparable from the object itself. An analogy could be drawn between a manager of a firm who wants to cut costs, yet is unwilling to reduce any of the factors of production in order to achieve this. Furthermore, we can say that pleasure is pleasure from some fairly specific experience - someone who thinks they will obtain pleasure from drinking a glass of wine would not refer to having it poured down their throat as they slept. When we say we obtain pleasure from something, we are referring to a specific experience. Nonetheless, there is no way in which pleasure can be separated from the thing in which it is contained.
Both of these arguments, therefore, have been shown not to carry much force, and Mill's first premise may be taken as being sound. We must next challenge the assumption that what is actually desired is good, or, that people desire their own happiness. This is infinitely more controversial than the previous point. The view Mill takes that what is actually desirable is desired has been repeatedly attacked as simply not being the case. Instead, it is pointed out, desirable means "ought to be desired" as opposed to "can be desired." The most famous attack on this point came from Moore in his Principia Ethica, where he illustrates the above mistake by saying that, in the same way as desirable must mean "ought to be desired," detestable means "ought to be detested," as opposed to "what can be detested." Moore's opposition is to the definition of "desired" as "good," as it is open to argument whether what people desire is good or not. For example, a person may desire some form of revenge, or may be a sadist, and as a result, would want people to suffer. According to Mill, because this is desired, it is good, yet it would probably be commonly agreed that revenge and sadism are morally wrong. In this area, therefore, utilitarianism has surely failed.
It can, however, be argued that our desires are not infallible, and we are capable of desiring that which is not pleasurable, and not desiring something that is pleasurable. However, I do not believe that this negates the point made above about revenge and sadism - the desirer of these virtues does so because it is pleasing to him, although not necessarily to society as a whole. Thus he is being entirely consistent with the principle which Mill set out; that what people desire is their own happiness; my seeking revenge on someone would bring me happiness, although it may harm society as a whole. Desires can therefore go wrong and, as Mill himself suggested, the theory of utility is not watertight. So Mill is mistaken in his belief that the evidence that something is desirable is the fact that it is desired; as we have seen, this is not always the case.
The difficulties encountered with the second point will surely mean that the transition between second and third is made more difficult. If it has been shown that what people desire does not always correspond to what is actually desirable, then it follows that individuals do not always desire the happiness of the whole community. Although people may be acting consistently with the maxim that everyone desires their own happiness, it does not follow that each person's own happiness is good to everyone, as the example above illustrates.
Even if the second assumption was not flawed in practice, and everything that individuals desired was desirable, it would still not be possible to go from saying that "each man's X is Y to him" to "every man's X is Y to everyone." For example, if X represents "dreams", and Y "fascinating," we have that each man's dreams are fascinating to him (which is reasonable enough), but also every man's dreams are fascinating to everyone else (which clearly is not). Now while some parts of everyone's dreams may be fascinating to some people, it cannot be said that every part of everyone's dreams are fascinating to everyone. In the same manner, if each man's happiness is good to him, it implies that each man finds some part of the general happiness good to him, and every part of the general happiness good to someone; what it does not imply is that the total general happiness is good to everyone. This is what Mill seems to be attempting to say. However, in a letter to Henry Jones who had raised the question of this interpretation, Mill states that this is not his intention; rather, he meant to imply that, since each individual's happiness is a good, the sum of these goods must also be a good. This is what Mill means by the general happiness being a good.
The final stage in Mill's argument is to argue that only happiness is desired in itself. However, he himself points out that people desire things such as virtue. Yet he does not, as one might expect, say that they desire it for the happiness it brings; instead, he believes that virtue has become a part of the end of happiness through the continued pursuit of it. In other words, people start off by desiring virtue for the happiness it yields, and, as time goes by and the happiness becomes closely associated with the act of being virtuous, the virtue becomes desired as much as the happiness itself, because being virtuous is synonymous with happiness, and therefore virtue has become a part of the end as well as a means to the end.
Mill also uses the example of the love of money as an illustration for his theory. People, he says, love money not because it itself, as a collection of paper notes and metal coins, has value, but because it can be used to obtain pleasure; however, as people continue to use money, it becomes a part of people's perception of happiness. In this way, the desire for money can be even greater than the desire to use it, and that has become a part of the end as opposed to a means to the end of happiness itself.
Moore was not impressed by what he saw as Mill trying to paper over the cracks in his own argument. Moore says that the notion that the coins and notes that were referred to above cannot possibly be a part of the end; how can they contribute in themselves to pleasure or the absence of pain? He maintains that, in order to acknowledge that people desire things other than happiness and pleasure in themselves, Mill has had to "bend" the rules of utilitarianism in order to incorporate them, rather than abandon his hedonistic principles.
Once again we can see that Mill's "proof" is open to criticism. However, at the very end of Chapter 4, he leaves it up to the reader to consider the evidence he has produced, and to decide for themselves whether or not to accept utilitarianism. His theory is not as hopeless as some critic might suggest, but it is undeniable that there are some grave inconsistencies in his account. When examining utilitarianism, it may, therefore, be a better approach to consider it a starting point that can be improved upon when on a quest to find an acceptable moral theory, rather than a solid, inflexible doctrine in itself.