Derek Parfit (1984), Reasons and Persons, Oxford: Clarendon Press, xv + 543 pp. (ISBN 0198246153; LCCN 83015139). Reprinted with corrections, 1986 (ISBN 019824908X); online on Oxford Academic, 2003 — DOI-10.1093/019824908X.001.0001
On the citation. The brief’s details are right: Parfit, Reasons and Persons, Oxford University Press, 1984; the imprint is the Clarendon Press. Two things to add:
- Identifier. The only DOI is for the 1986 reprint as put online in 2003, which Crossref dates 23 January 1986 (print) and 1 November 2003 (online). The page ranges below are that printing’s; Open Library gives the same pagination (xv, 543 pp.) for both printings.
- Date.
published:is the 1984 first edition, by year only, since no source I reached gives a month.
Key takeaways
Registered from the publisher’s description, the author’s abstract and the chapter abstracts, not a reading. What follows is what the book says about itself.
The author’s abstract describes four parts:
- Part One discusses “some ways in which theories about morality and rationality can be self-defeating”, giving aims while telling us “to act in ways that frustrate these aims”.
- Part Two discusses what one person can rationally want or do at different times, against what different people can, and “the rationality of four attitudes to time: temporal neutrality, and the three kinds of bias towards the present, the near, and the future”.
- Part Three discusses personal identity: “Most of us, I argue, have certain beliefs about this subject that are false, but hard to give up. If we accept these claims, they may change some of our emotions or attitudes, and we should revise some of our beliefs about both rationality and morality.”
- Part Four discusses obligations to future generations. “The most difficult question here, which I fail to answer, is about the relative importance of the number of people who will exist, and the quality of life of these people.”
Part III’s six chapters, as their abstracts on Oxford Academic describe them (pages of the 1986 printing):
- “What We Believe Ourselves to Be” (pp. 199–218): numerical and qualitative identity; the Physical Criterion (“the continued existence of enough of our brain”) and the Psychological Criterion (“overlapping chains of psychological continuity and connectedness”); our belief that our identity “must be determinate”.
- “How We Are not What We Believe” (pp. 219–244): the Psychological Criterion is not circular; Cartesian egos and how a non-reductionist view “might have been true”; “spectrum arguments against both the Physical and Psychological Criteria”.
- “Why Our Identity Is not What Matters” (pp. 245–280): brain bisection, the unity of consciousness, and full division, “why neither of the resulting people would be us; why this would not matter, since our relation to each of these people contains what matters in the prudential sense”.
- “What Does Matter” (pp. 281–306): whether the body matters; “why it does not matter whether psychological continuity has its normal cause”; the Branch-Line Case, series-persons, partial survival and successive selves.
- “Personal Identity and Rationality” (pp. 307–320): an argument “against the Classical Self-interest Theory”, with a discount rate “with respect to the degree of psychological connectedness” rather than time.
- “Personal Identity and Morality” (pp. 321–348): autonomy and paternalism, desert, commitments, and the separateness of persons, with “a reductionist view” giving “some support to the utilitarian rejection of distributive principles”.
Appendices relevant to Part III, by title: “Nagel’s Brain” (pp. 469–477), “The Closest Continuer Schema” (pp. 478–479) and “Buddha’s View” (pp. 503–504).
Standing in the record
Filed on 2026-10-02 at the owner’s request, as the long form of the
personal-identity line the record is filling out. Deferred: the book is in
copyright, the reachable scans are lending-only, and the brief’s rule for
books is to register from the publisher’s description and contents and not
to reconstruct the argument from summaries. No NOTE is filed.
The record already relies on it at second hand, which is the case for reading it:
- Birch (LIT-111, NOTE-183) argues from “Relation R”, this book’s term, that a chatbot character has no persisting bearer, and his no-scan teletransporter turns on the question the chapter “What Does Matter” addresses, whether psychological continuity must have its normal cause. By that chapter’s abstract, Parfit holds that it need not. If so, the book would weaken Birch’s argument, not support it. That cannot be settled without reading the chapter.
- Velleman (LIT-292, NOTE-268) reads Frankfurt’s late view as Parfitian by citing this book’s pages on character and valued traits.
- The identity-and-ethics survey (LIT-130, NOTE-166) cites it for fission, for the Russian nobleman, and for reductionism weakening the separateness of persons.
- Sebo’s review (LIT-166, NOTE-116) puns on Part IV’s Repugnant Conclusion (“Rebugnant conclusion”).
The paper version of Part III’s core, “Personal Identity” (1971), is filed beside it and was read in full; its NOTE is the record’s account of the argument until this book is read. Williams’s “The Self and the Future” and Lewis’s “Survival and Identity”, also filed beside it, are a challenge the 1971 paper answered and a reply to that paper; whether the book takes either up could not be checked. Locke and Hume, filed the same day, are its ancestors. The book carries no instruction for machine-learning practice, and no anthology topic holds it.
Priority for a reading: high. Two of the record’s readings already depend on claims from it that only its text can settle, and its chapter on whether continuity needs its normal cause decides the record’s question about AI interlocutors. A lawful full text would most likely be a library copy; the owner may hold one.