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Non-Identity Matters, Sometimes


Suppose the only difference between the effects of two actions is to whom they apply: either to parties who would – or would not – exist if the actions were not performed. Is this a morally significant difference? This is one of the central questions raised by the Non-Identity Problem. Derek Parfit answers no, defending what he calls the ‘No-Difference View’. I argue that Parfit is mistaken and that sometimes this difference is morally significant. I do this by formulating a familiar kind of example in a new way. I make use of some findings in social psychology to help deflect counterexamples to my view. I then show how my view withstands Parfit's latest argument in favour of the No-Difference View. I conclude with a brief discussion of some questions my argument raises for consequentialist moral theory.

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1 Parfit Derek, Reasons and Persons (Oxford, 1984), p. 351.

2 Parfit, Reasons and Persons, p. 358.

3 It has been argued that this judgement rests on a faulty (comparative) view of harm. I leave aside that dispute here, but for defences of a non-comparative view of harm see, for example, Shiffrin Seana, ‘Wrongful Life, Procreative Responsibility, and the Significance of Harm’, Legal Theory 5 (1999), pp. 117–48; Harman Elizabeth, ‘Can We Harm and Benefit in Creating?’, Philosophical Perspectives 18 (2004), pp. 89113; and Molly Gardner, ‘Misfortune and Inevitability’ (unpublished manuscript).

4 This is similar to the formulation of the problem on page 50 of Hanser Matthew, ‘Harming Future People’, Philosophy and Public Affairs 19 (1990), pp. 4770.

5 Schwarz Thomas, ‘Obligations to Posterity’, Obligations to Future Generations, ed. Sikora R. and Barry B. (Philadelphia, 1978), pp. 313.

6 Parfit, Reasons and Persons, p. 367, and On What Matters, vol. 2 (Oxford, 2011), p. 219.

7 Parfit, Reasons and Persons, p. 367.

8 I understand the No-Difference View to be fundamentally an axiological claim that Parfit takes to have deontic import. It is because non-identity makes no difference to the outcomes that it does not affect our reasons for acting. However, whether the no-difference view is fundamentally axiological or deontic does not affect the following argument.

9 The deafness decision is based loosely on a story reported in Liza Mundy, ‘A World of Their Own’, Washington Post Magazine (Sunday, 31 March 2002), p. W22.

10 I acknowledge that this assumption is not without controversy. If you disagree with this assumption, substitute for deafness an alternative condition that you believe makes a person somewhat badly off.

11 The parents in the news article on which the deafness cases are based defended their choice to conceive a deaf child in part out of what they took to be benevolence: they thought they would be better able to care for a deaf child. See Mundy, ‘A World of Their Own’.

12 Parfit, Reasons and Persons, p. 367 and On What Matters, vol. 2, p. 221.

13 Parfit, Reasons and Persons, p. 368.

14 Though see n. 10.

15 Kahneman Daniel and Tversky Amos, ‘Prospect Theory: An Analysis of Decision under Risk’, Econometrica 47 (1979), pp. 263–92.

16 Often attributed, falsely I am told, to Stalin. Another relevant quote is from Teresa Mother: ‘If I look at the mass I will never act. If I look at the one, I will’, in Paul Slovic, ‘ “If I look at the mass I will never act”: Psychic Numbing and Genocide’, in Judgement and Decision Making 2 (2007), pp. 7995.

17 Slovic, ‘Psychic Numbing and Genocide’.

18 For a discussion of order bias in philosophy, see Swain Stacey, Alexander Joshua and Weinberg Jonathan M., ‘The Instability of Philosophical Intuitions: Running Hot and Cold on Truetemp’, Philosophy and Phenomenological Research 76 (2008), pp. 138–55, and Unger Peter, Living High and Letting Die (Oxford, 1996), p. 93 and ch. 4 more generally.

19 Parfit, Reasons and Persons, pp. 361–9.

20 Parfit calls this the ‘Equal Weight version of Temkin's View’ (Parfit, On What Matters, vol. 2, p. 227), which is itself a version of what he calls the ‘Two-Tier View’ (Parfit, On What Matters, vol. 2, p. 219).

21 Parfit, On What Matters, vol. 2, p. 228.

22 See, for example, David Boonin's forthcoming book on the Non-Identity problem.

23 The view is called the Adjusted Value View and is defended in Gardner Molly and Weinberg Justin, ‘How Lives Measure Up’, Acta Analytica 28 (2013), pp. 3148. Briefly, it assesses a person's well-being by taking into account how well-off the best-off relevant person is. Applied to Parfit's Case Six, and taking lifespan as a proxy for a life's value, the Adjusted Value View directs us to take Bernard's 90 in B as the ideal to which we compare all of the affected parties, subtracting from the others the shortfall between the value of their lives and 90. So in A, Adam's life gets adjusted down to 50 (70 − (90 − 70) ) and Bernard's life gets adjusted down to −10 (40 − (90 − 40) ), for a total of 40. In B, Bernard's life remains at 90 (90 − (90 − 90) ) while Charles’ life gets adjusted down to −70 (10 − (90 − 10) ), for a total of 20. In C, Charles's life gets adjusted down to 10 (50 − (90 − 50) ) and David's life gets adjusted down to −50 (20 − (90 − 20) ) for a total of −40. Compared to the No-Difference View, our evaluations of the outcomes have changed, so non-identity does make a difference, but the relative rankings of the outcomes have not: A (40) is superior to B (20), which in turn is superior to C (−40).

24 Earlier versions of this article were presented under the title ‘When Non-Identity Matters’ at the 2011 meetings of the South Carolina Society for Philosophy, the International Society for Utilitarian Studies, and the Rocky Mountain Ethics (RoME) Congress. I would like to thank the audiences at these meetings for their criticisms and questions, Doran Smolkin for his commentary on the paper at RoME, the anonymous referees for this journal, and its editor, Brad Hooker.

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