Source: Benatar, David. Better Never to Have Been (2008 1 edn). pp. 171-172.

  Although the impersonal average view also solves the nonidentity problem, it too cannot be Theory X, for it faces other problems. To show why this is the case, Derek Parfit asks us to imagine another two worlds. In the first world everybody had a very high quality of life. In the second world, in addition to all these people with their same high quality of life there are additional people who, although not quite as well off, nonetheless have lives that are well worth living. These sorts of cases, Derek Parfit calls ‘Mere Addition’. More specifically, mere addition occurs ‘when, in one of two outcomes, there exist extra people (1) who have lives worth living, (2) who affect no one else, and (3) whose existence does not involve social injustice’.²²
  Now the impersonal average view says that the second world is worse, because [4.] the average quality of life is lower. It is made lower by the mere addition of extra people who, although happy, are not quite as happy as the original people are. Derek Parfit takes this to be implausible. It would entail, he says, that [5.] it would be worse if in addition to Adam and Eve leading blissful lives, there were a billion extra people who lived lives of slightly lower quality. The impersonal average view also entails, he says, that whether it is wrong to have any given child depends on facts about the quality of all previous lives. Thus, if [6.]‘the ancient Egyptians had a very high quality of life, it is more likely to be bad to have a child now’.²³ But, says Professor Parfit, ‘research in Egyptology cannot be relevant to our decision whether to have children.’²⁴ Accordingly, he takes the impersonal average view to be implausible.

 ²² Parfit, Derek, Reasons and Persons, 420. ²³ Ibid. ²⁴ Ibid.

I acknowledge that most parents nowadays don't mull reproduction that thoroughly, but Parfit's outlook feels wrong to me. How can't a reasonable person:

  1. mull (4)-(6) overhead as factors in a decision to reproduce?

  2. be dissuaded and thwarted from procreation by (4)-(6)?

1 Answer 1


You might find the following extract helpful in explaining Parfit's rejection of the impersonal average view. It takes a simple case but this makes the key point more clearly. Page references are to Parfit's Reasons and Persons (1986).

[First we note] the Total Principle, which measures the value of outcomes by summing the net quantities that different persons enjoy in them of "whatever makes life worth living" (p. 387). This view allows the value of an outcome to be improved by the addi- tion of sheer numbers of persons, so long as their lives are at least minimally worth living.

The most discussed alternative to the Total Principle for evaluating outcomes in terms of quality of life has been the Average Principle, which awards the prize to the outcome in which the average quality of life is highest. The Average Principle does in- deed avoid the Repugnant Conclusion, for it awards no points for the addition of happy people, unless they are average-raisers. But Parfit quite rightly dismisses the Average Principle as implausible because it has such consequences as that the addition to the world of a person who will have a very good life can make the outcome worse just because other people have lives that are even better (pp. 420-422). (Robert Merrihew Adams, 'Should Ethics be More Impersonal? a Critical Notice of Derek Parfit, Reasons and Persons', The Philosophical Review, Vol. 98, No. 4 (Oct., 1989), pp. 439-484 : 472.)



The Repugnant Conclusion: For any possible population of at least ten billion people, all with a very high quality of life, there must be some much larger imaginable population whose existence, if other things are equal, would be better, even though its members have lives that are barely worth living (p. 388).



Robert Merrihew Adams, 'Should Ethics be More Impersonal? a Critical Notice of Derek Parfit, Reasons and Persons', The Philosophical Review, Vol. 98, No. 4 (Oct., 1989), pp. 439-484.

Derek Parfit, Reasons and Persons,ISBN 10: 019824908X / ISBN 13: 9780198249085 Published by OUP Oxford 1986-01-23, Oxford, 1986.

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