Book · 1984
Reasons and Persons
by Derek Parfit
Derek Parfit dismantles self-interest, personal identity, and population ethics — then hands you the rubble and asks what you're going to do with it.
What does Reddit think of Reasons and Persons?
Twenty-eight mentions over seven years, 26 distinct commenters, almost entirely in r/askphilosophy (27 of those 28). That concentration tells you something: this is a book that gets cited by people answering hard questions, not by people looking for their next read. It lands on recommended-reading lists alongside McDowell, Brandom, and Williams — the heavy-hitter tier — and when it surfaces in threads, it usually does so to name something precisely. The "self-effacing" argument against egoism (↑64) is the signature move Reddit reaches for: Parfit's own vocabulary doing work in someone else's argument. The personal identity threads invoke it for the teleporter problem (↑32). Activity peaked in 2024 with 8 mentions. No serious criticism appears in the data — not because the book is beyond criticism, but because the people citing it already know they're in the deep end and aren't complaining about the water.
Community feedback & reader fit
Themes
- · Personal identity and psychological continuity
- · Self-defeating moral theories
- · Population ethics and the non-identity problem
- · Rationality and self-interest over time
- · Reductionism about persons
Common praise
- + Gives philosophers a shared vocabulary — "self-effacing", "reductionism" — that threads on r/askphilosophy still reach for unprompted.
- + The teleporter and fission cases make the personal-identity argument concrete enough to settle debates in 32-upvote comment chains.
- + Consistently appears on the same r/askphilosophy recommended lists as McDowell and Brandom, suggesting readers treat it as canonical, not optional.
- + Lands original arguments against egoism that feel tighter than the standard utilitarian critiques — the self-effacing point earns ↑64 on its own.
Common criticism
- − The Reddit data surface no critical takes, which may say less about the book than about who is citing it — no one shows up to a Parfit thread to complain the book is too long.
- − With only 28 total mentions across 7 years, it draws specialists rather than a broad audience, so crowd-sourced caveats are thin.
Who it's for
If you already know what "psychological continuity" means and you keep ending up in the same r/askphilosophy threads, this is the book everyone is quoting. Readers who want professional-grade tools for arguing about personal identity, population ethics, or rational self-interest will find Parfit supplies the apparatus directly. Not the entry point — it appears on lists alongside Word and Object and Making it Explicit, which signals the expected preparation level. If the teleporter thought experiment already bores you, skip it; if that sentence just made you curious, start here.
Mentions over time
Top subreddits
Which Reddit comments matter for Reasons and Persons?
Top-upvoted quotes across the subreddits where this book is mentioned. Click through to read the full thread.
“You're going to have a long list. * *Truth and Truthfulness*, Bernard Williams * *Shame and Necessity*, Bernard Williams * *Word and Object*, W.V.O. Quine * *Mind and World*, John McDowell * *Reasons and Persons*, Derek Parfit * *Sense and Sensibilia*, J.L. Austin * *Culture and Value*, Ludwig Witt…
“Here's a few: John McDowell, *Mind and World* Robert Brandom *Making it Explicit* Michael Thompson *Life and Action* Charles Taylor *Sources of the Self* Richard Rorty *Philosophy and the Mirror of Nature* Irad Kimhi *Thinking and Being* Alasdair MacIntyre *After Virtue* Derek Parfit *Reason…
“I feel like some of the most powerful arguments against egoism are the ones which suggest that it's not in your interests to be an egoist. (To borrow a term from Parfit's *Reasons and Persons*: egoism is "self-effacing", in that it commands its followers to *stop* following it.) There are basicall…
“This post spells out the most cited works in the Stanford Encyclopedia of Philosophy (circa 2020), as well as their date of publication: That yields a decent rule of thumb guide to the most important work in th…
“I’m not sure you read my reply. You seem to just be insisting that there haven’t been major breakthroughs in moral philosophy and also that in order for ethics to be legitimately objective it must somehow be similar to this completely different area on inquiry. Here are some major breakthroughs in…
“This is a widely discussed question in philosophy, and the answer depends on your view of what determines personal identity. In Reasons and Persons, Derik Parfit argues that psychological continuity is what matters for personal identity. Based on this, he concludes that if your body was destroyed a…
“Here are some suggestions: Anything by Plato (The collection "Five Dialogues" would be a particularly good place to start) *Existentialism is a Humanism* by Jean-Paul Sartre (existentialism, very short) *Problems of Philosophy* by Bertrand Russell (analytic tradition) *The Life You Can Save*…
“It’s an old discussion—goes back to antiquity (e.g., Seneca), and Bacon, and many others. There is a fairly common view that death itself can’t be bad, but dying is often quite bad. The ethical upshot of that is pretty obvious: making dying less bad is good. There are other arguments for the badness…
Convinced? Pick up Reasons and Persons
What else does r/askphilosophy read?
Other books mentioned in the same sub, ranked. Shared-sub overlap with this title breaks ties.
Critique of Pure Reason
Immanuel Kant
Kant's 1781 attempt to settle the limits of human knowledge — the book that split philosophy in two and still hasn't been fully digested.
The Myth of Sisyphus
Albert Camus
A 1942 essay that opens with the question of whether life is worth living and ends by insisting Sisyphus is happy.
Tractatus Logico-Philosophicus
Ludwig Wittgenstein
Wittgenstein built a numbered ladder from logical atomism to the inexpressible, then said the ladder had to be discarded once you climbed it.
Being and Time
Martin Heidegger
Heidegger's argument that human existence only gets its meaning from death — 162 Reddit mentions, mostly from people explaining why it's so hard to read.
Nicomachean Ethics
Aristotle
Aristotle's 2,400-year-old argument that living well depends on virtue, leisure, and the company you keep — still the canonical text for the field.
Beyond Good and Evil
Friedrich Nietzsche
Nietzsche dismantles the moral framework Western civilization built on, then refuses to tell you what to replace it with.
Reasons and Persons — frequently asked
What does Reddit actually use Reasons and Persons for?+
Mostly as a citation weapon. In r/askphilosophy threads on egoism, identity, and population ethics, commenters pull Parfit's vocabulary — "self-effacing", psychological continuity — to sharpen an argument rather than to recommend the book to newcomers. The ↑64 comment on egoism is the clearest example: one concept, borrowed from Parfit, does all the work.
Is Reasons and Persons suitable for someone new to analytic philosophy?+
Probably not as a first book. On r/askphilosophy it consistently appears alongside McDowell's Mind and World and Brandom's Making it Explicit — both demanding texts — which signals the implicit reading-level expectation. The 28-mention, 26-commenter data skews toward people who already have philosophical training and are looking for the source text behind a concept they've already encountered.
How frequently does Reasons and Persons come up on Reddit?+
28 mentions over 7 years, almost all (27) in r/askphilosophy. Activity varied: 1 mention in 2019, a spike to 7 in 2021, then 8 in 2024.
Does Reddit have any criticism of Reasons and Persons?+
None visible in the tracked data. That absence likely reflects who's citing it — specialists invoking it to win arguments don't pause to critique it in the same thread. The book's difficulty may also filter out casual readers who'd push back. Take the clean record as a note about audience self-selection, not as a verdict on the book.