StonemindOne question a day.
Carved in stone.
A classic philosophical dilemma every day — a real thought experiment from a real book. Read it, think it through, give your answer and your reason, then carve it into marble. See where the great minds stand, argue with Socrates, and challenge a friend.
- No sign-up
- 373 classic dilemmas
- Six halls
- 9 languages
The Experience Machine
after Robert Nozick, Anarchy, State, and Utopia (1974)
Would you plug in to the experience machine for the rest of your life?
Leaning: Stay in reality
A demo of the real thing. In the app, a carved answer is final.
Read. Think. Answer. Carve.
About as long as a cup of coffee. There is no right answer to find — only yours, and the reason you give for it. Once you've carved, see how the rest of the world answered — real totals only, and “be among the first” until there are enough.
Read
A short story told in plain words — a real thought experiment from a real book or paper, set somewhere you can picture.
Think
Three “ask yourself” questions turn it over: what you assume, what would change your mind, where the hard part is.
Answer
Place yourself on a scale between two poles, or name a third way. Then write your reason in a sentence or two.
Carve
Your draft stays editable until 23:59. When you're sure, press and hold to carve it. At midnight, an uncarved draft is carved as written.
A stone that ages with you
Every carved day ages a stone of your own. Miss a day and it cracks, and the streak begins again — unless you answer yesterday's dilemma in time, or a stoic rest day covers it. The gold you've earned is never taken back.
Every carved answer goes on your shelf, so you can see what you thought a month ago — and whether you still do.
From day oneRawPlain white marble, waiting.
After 7 daysVeinedThe first grey veins appear.
After 30 daysThreads of goldGold runs through the cracks. Once earned, it stays.
After 365 daysGolden marbleA year of answers, in one stone.
Then hear the other side
See where Kant, Mill, Hume and hundreds of others would stand on the same scale. Let Socrates question your answer before you carve it, or argue it out with a thinker yourself.
The verdicts
PremiumHundreds of thinkers placed on the same scale as your answer, with the one closest to you named.
The book & the lesson
PremiumWhere each dilemma first appeared, what to read next, what it teaches, and where it shows up in the real world.
Socrates
Free to tryQuestions that test your answer while it is still a draft. Three are free to try.
Against you & the steelman
PremiumThe strongest case against your answer — and the best case for the side you rejected.
Talk to a thinker
PremiumA conversation with one of 26 great minds, from Socrates and Seneca to Kant, Mill, Nietzsche, Beauvoir and Parfit — an AI interpretation, never a quotation.
My situation
PremiumBring a real choice from your own life and see it as a classic dilemma, with Socrates and a steelman beside you.
Book of the month
Free to tryCarve five answers in a month and get one real book chosen for the way you think — with the reason why.
The AI answers in the language you write in. It is written by Claude, by Anthropic: it can be wrong, it is not professional advice, and a thinker's replies are an interpretation of their ideas — never a quotation.
Six halls, 373 dilemmas
The thought experiments philosophers have argued over for two and a half thousand years — from Plato and Zeno to Parfit, Nozick and the questions machines are raising now.
Ethics
What should you do?
- The Drowning Child
- The Murderer at the Door
- The Ring of Gyges
Mind
What is it to think and feel?
- Mary's Room
- The Chinese Room
- Buridan's Ass
Self & Identity
What makes you you?
- Grandfather's Axe
- Splitting in Two
- The Same River Twice
Society & Justice
How should we live together?
- Gamble Behind the Veil
- The Ones Who Walk Away from Omelas
- The Noble Lie
Knowledge & Truth
How can you be sure?
- The Brain in a Vat
- Newcomb's Problem
- Fake Barn Country
Meaning & Death
What makes a life worth living?
- The Experience Machine
- Sisyphus Happy
- The Death of Ivan Ilyich
Tree & timeline
See how the ideas descend from one another, and walk them through five eras.
Words to know
Every term you meet is explained in the story and kept in your own dictionary.
Theme weeks
Seven days on one question — free will, justice, the self — 39 weeks in all.
Packs
Extra sets of eleven: Ethics of AI, Dilemmas of Love, Life & Death, All of Kant.
What you think, over time
One answer is an opinion. A shelf of them starts to show who you are — and where you've changed.
Your beliefs
Not a personality type — what your answers actually suggest you believe: outcomes or duties, freedom or fairness, loyalty or impartiality. Tap “Not me” if it's wrong.
Monthly exam
Five questions on a hall you've explored. Get four right and a seal goes on your shelf.
Time capsule
Seal an answer for a year. On the day it opens, see whether you still agree with yourself.
Letters from the past
Thirty days after you carve, your answer comes back: would you carve it again?
Book of Answers
Every answer you've carved, with your doubts and changed minds, as a PDF made on your phone.
Your year in philosophy
Each December: the stones you carved this year, what your stone became, and how often you changed your mind — and said why.
Argue with ideas, not people
A dilemma gets better with someone who sees it differently. All of this is free.
Every post is checked by a filter before it appears. Anything can be reported or blocked from the ⋯ menu, and a person reviews every report within 24 hours. Zero tolerance for attacks, hate and harassment.
Read the community rules →Duels
Challenge a friend on a dilemma you've carved. They answer in the app — or in their browser, no app needed — and you see both sides.
The Agora
Once you've carved, read the strongest arguments on both sides, add your own in 280 characters, and mark the ones that land. Each week the best win a laurel.
Clubs
Up to twelve people, one shared dilemma a day, answers that stay inside the club.
Debates
Three rounds, one to one, with someone who answered the other way. Anonymous. If no one is free, an AI opponent steps in.
On your home screen, in your language
Widgets
Today's question and your streak on the home screen and the lock screen.
A card to share
Turn any carved answer into a marble inscription card — for your stories, a message, or your photos — and ask what they would carve.
iCloud backup
Your journal is copied to your own private iCloud as you go, and comes back when you reinstall or move to a new iPhone.
9 languages
- English
- Deutsch
- Español
- Français
- Italiano
- 한국어
- Português
- Русский
- Українська
What you write stays yours
No sign-up, no ads, no analytics, no tracking. Your written reasons stay on your phone and in your private iCloud — unless you send one in a duel, post it, or ask the AI about it. The daily dilemma works offline.
Read the privacy policy →- No sign-upNo email, no password. An anonymous ID is created when you first carve, never linked to your name.
- Counted, not readWhen you carve, only your place on the scale is sent, so the world's answers can be totalled. Your reason stays with you.
- AI only when you askAn AI feature sends only the text it needs, through our server to Anthropic. Our server doesn't store or log it.
- Erase it allOne button erases your data from your phone, your iCloud and our server.
Before you begin
The unexamined life
A few minutes a day to think it through
One question, your own answer, set in stone. Then tomorrow, another.