Preshus asked:

Mill claims that each person’s happiness is a good to that person. He then concludes from this that the general happiness is therefore a good to the aggregate of all persons. Is this a good argument?

Answer by Craig Skinner

No. It’s a bad one, showing an elementary logical fallacy. But Mill disclaims it. He is a better logician than some critics allow.

Let me elaborate.

The Argument:

The fallacy is the Fallacy of Composition: that something true of a thing is also true of an aggregate of these things.

For example: an atom is hard to break; porcelain is made of atoms; so porcelain is hard to break.

The aggregate of all persons is not itself a person and doesn’t have a good in the sense that a person can have a good.

The general happiness can be high without a particular person being happy at all.

Furthermore, the fact that my happiness is good for for me, and yours good for you, doesn’t logically entail that mine is good for you, or yours for me.

Mill’s Disclaimer:

Mill’s text is a bit unclear. But in a letter written some years afterward (1868), included in his Collected Works, he says he didn’t mean to imply that another’s good is a good for me, only that it is a good FULL STOP (a good ‘simpliciter’ as philosophers say). Thus, my happiness is a good, yours is a good, everybody else’s is a good. So the aggregate of all these is a good. Fair enough.

His position, using happiness as an agreed good, is similar to Kant’s position using rationality as an agreed good:

Kant assumes each sees herself as an end (rational nature being an end in itself). This commits her to the value of the ends of others (since they, like her, are rational beings).

Mill assumes each sees her own happiness as an end (happiness being a good in itself). This commits her to the value of happiness in others (since they, like her, view their happiness as a good).

Mill the Logician:

Mill’s System of Logic (1843) was the standard textbook on the subject. It is curious, therefore, that several accusations of elementary logical blunders were levelled against him. In addition to the one discussed above, two others were cited (with some glee) by Moore, an early 20th Century academic philosopher, then influential, now largely forgotten. These were:

1. The Fallacy of moving from fact to value, from ‘is’ premises to an ‘ought’ conclusion.

Mill has a notorious passage where he draws an analogy between ‘visible’ and ‘desirable’. Moore accuses Mill of sliding from ‘desirable’ meaning what people actually desire (fact; and here ‘desirable’ is analogous to ‘visible’) to ‘desirable’ meaning what people ought to desire (value; and here ‘desirable is not analogous to ‘visible’). But Mill is not guilty. The most he claims is that in deciding what ought to be desired, we should take account of what is actually desired. Mill was well aware that people sometimes desire bad things, and that what we desire is no sure guide to what we ought to desire. He says that what people desire is the ‘sole evidence’ and ‘all the proof the case admits’, he does not suggest logical entailment.

2. The Naturalistic Fallacy.

Moore, accusing Mill of trying to define ‘good’ in naturalistic terms, declares (correctly) that one can always sensibly ask of any such definition the question ‘But is it good?’ (the Open Question Argument). But again Mill is not guilty. He shows no interest in defining words, in naturalistic terms or otherwise.

The most that can be said is that Mill’s prose is sometimes not completely clear. But that is something of which most philosophers, great and not-so-great, are guilty, some very great ones notoriously so.