Personal Identity and the Ethics of Future Selves

Parfit's reductionism about personal identity was never intended as a purely metaphysical exercise; in Part III of Reasons and Persons (1984) he draws out its direct implications for practical reason and ethics. If psychological connectedness to one's own future self is a matter of degree rather than an all-or-nothing fact of identity, then the special, categorical weight ordinary prudential reasoning gives to one's own future welfare, as against the welfare of other people, becomes harder to justify on purely rational grounds — connectedness to one's distant future self may, on this view, be weaker than connectedness to a close friend or family member in the near term, undermining any sharp, principled line between self-interest and other-regarding concern.