Mill's proof of utilitarianism: moving from the individual to the aggregate

Question

OK, so:

In Utilitarianism, specifically Chapter IV, Mill claims that

...each person’s happiness is a good to that person, and the general happiness, therefore, a good to the aggregate of all persons.

Now, putting potential objections to Mill's "inductive" proof of utilitarianism aside, I have a question on interpretation. Now, in moving from the individual to the aggregate, I have seen accusations that Mill has committed the fallacy of composition here - but Mill writes elsewhere that

...when I said that the general happiness is a good to the aggregate of all persons I did not mean that every human being's happiness is a good to every other human being...

But I fail to see how this can be so: surely any talk of aggregates - if we suppose that all Mill's proof tells us is that we should each care for our own happiness - is meaningless. We do not care at all about the "General Happiness", unless, that is, it happens to involve our own happiness being increased -- which in any case does not amount to the claim that we should care about the General Happiness in itself.

Can someone please offer a possible explanation of Mill's argument here? Have I misunderstood him? Am I missing something? Or is Mill just wrong here?

It just seems to be that, if Mill wants to talk about individuals valuing the happiness of the aggregate, he has to add on additional moral strictures -- namely that we actually should care about others. (Edit: or, speaking practically, maximising the general happiness is the best way to achieve individual happiness. But I fail to see how this could be so).

Answer 1

Your criticism of Mill is right under the social choice perspective. The general happiness is warranted only if the lexical order of preferences of individuals is the same. I like Chinese over Mexican, and you too, so going to a Chinese restaurant maximizes our general happiness. But if you like Mexican over Chinese, then which restaurant should we go to maximize our general happiness? Kenneth Arrow earned an economics Nobel Prize by proving the impossibility of a decision procedure that aggregates all preferences of differing lexical orders. Under the social choice view, Mill can be argued to be mistaken when he conjoined the two statements that you highlighted.

Mill's conjoining the statements however can be defended from a different angle, without the postulate of altruism. In fact, Mill believes that altruism is unnatural. Mill was affected and impressed by the communist movement of his time (19th century London is a place to visit!). Marx lived in the same town as Mill, and requested the acquaintance of Mill, which Mill declined. Mill even proposed his own socialist society in his Principles of Political Economy. To Mill, communism would fail since it is founded on unnatural view of human nature: altruism. To Mill, human nature is self-interested, not altruistic. The protection of one's interest by oneself is one of the reasons Mill argued for democracy. (cf. Considerations on Representative Government)

Mill believed that, when we reflect on maximizing our own self-interests, we inevitably realize that our utility calculation sometimes turns out to be wrong or is uncomputable due to inherent complexities (e.g., my preference order might change in the future). So it is prudent for each individual to champion general happiness as an insurance. Thus, Mill's society guided by the general happiness principle is based on this enlightened self-interest.

Answer 2

The 'Utilitarianism' (1861/63), ch. 4 quote reads in full :

'No reason can be given why the general happiness is desirable, except that each person, so far as he believes it to be attainable, desires his own happiness. This, however, being a fact, we have not only all the proof which the case admits of, but all which it is possible to require, that happiness is a good: that each person's happiness is a good to that person, and the general happiness therefore a good to the aggregate of all persons.'

One point is that Mill does not claim to offer a strict proof here, i.e. one that demonstrates the truth of his thesis - only 'all the proof which the case admits of'. He advances only 'considerations ... capable of determining the intellect'. That aside, and the central point, does Mill commit the fallacy of composition here ? Does he infer from each desiring their own happiness (a form of psychological hedonism he endorses) to each desiring the happiness of all ?

If Mill were to be making a purely psychological - psychological hedonist - claim that if each person desires their own happiness, then the aggregate of persons desires the happiness of the aggregate of persons, the broken-backed nature of the argument would be indisputable. It would be a straight fallacy of composition. But this isn't his claim. His claim is that it is by desiring the aggregate happiness we make the maximisation of our own happiness most likely. This is why 'the general happiness [is] a good to the aggregate of all persons'.

It must be admitted that Mill expresses himself clumsily. But put the point like this. Mill says that each person desires their own happiness. We can add, each person desires to maximise their own happiness. What is the most rational policy for achieving the maximisation of our own happiness ? It is to maximise the aggregate happiness. The assumption is that maximising the aggregate happiness will as a matter of fact maximise our own happiness or make its maximisation most likely. There is no fallacy in the argument with this assumption inserted.

But you might challenge : is this what Mill said or might have said or might have thought ? There is good evidence that Mill did make this assumption. In his 'Autobiography' he writes about the period after his nervous breakdown (1826):

'I never, indeed, wavered in the conviction that happiness is the test of all rules of conduct, and the end of life. But I now thought that this end was only to be attained by not making it the direct end. Those only are happy (I thought) who have their minds fixed on some object other than their own happiness; on the happiness of others, on the improvement of mankind, even on some art or pursuit, followed not as a means, but as itself an ideal end. Aiming thus at something else, they find happiness by the way.'

'Those only are happy (I thought) who have their minds fixed on some object other than their own happiness; on the happiness of others' : this is, I suggest, the assumption at work in the 'Utilitarianism', ch. 4 quote.

[Whether maximising the aggregate happiness will maximise our own happiness or make its maximisation most likely, I am none too sure. And I do not endorse psychological hedonism. But I set these matters aside in an examination of the logic of Mill's aergument.]

1. Tim Mawson, 'Mill's Proof', Philosophy, Vol. 77, No. 301 (Jul., 2002), pp. 375-405.
2. Mary Warnock, 'Utilitarianism : John Stuart Mill', London : HarperCollins, 1972, Introduction.