kensaurus

Field note · Living book

the wanting mind: a book about why we want, to read, hear and ask

A 36-chapter book on why we want, free to read with no ads or account. English narration, a map of 268 concepts, 22 simulations, and Ask the book.

Kenji Sakuramoto · kensaurus合同会社 ·

Why do people want? Why do some people take, and others give? I wrote a book to chase that question: 36 chapters that cross neuroscience, economics, philosophy and anthropology.

The question started when I lived in meritocratic Singapore and then came back to Japan, a country that runs on community and, in places, on a very clear hierarchy.

It came out at about 147,000 words. Read cover to cover, that is around eleven hours, and most people won't do that. So the book has other ways in, and it lives on the web and in apps for iPhone and Android.

Read it, hear it, follow it, ask it

You can read it in English, Japanese, Chinese or Thai, and switch language mid-chapter. The other three are translations of the English text.

All 36 chapters are narrated in English, about 20 hours in total. The voices are AI voices: twelve fictional narrators who take turns chapter by chapter. While a chapter plays, the word being read is highlighted in the text.

The 268 concepts in the book sit on one map, with the links between them. Tap a highlighted concept in the text to see what it means and which other chapters use it. Ideas like Piketty's r > g and the prisoner's dilemma come with 22 simulations, so you can move the numbers yourself and see what happens. There are 242 references, and you can open each source from the line that cites it.

The chapter 'The World Is Behaving Strangely' in English: the end of its plain-language summary, then the opening with a large drop cap. Along the bottom: a mini audio player and buttons for contents, search, narration, more and account.
Reading
A concept card opened by tapping 'extraction' in the text: the extraction–generation axis explained, a small graph of linked concepts, related concepts, and a list of the 33 chapters that mention it.
Tap a concept
English narration playing. The narrator is the fictional Marcus Cole, shown with an AI-made portrait. The text scrolls with the audio and the word being read is in bold. Position 0:56 of 22:08.
English narration
The concept map: 268 concepts as coloured dots linked by lines, with '268 concepts' and '1296 connections' in the footer.
The 268-concept map
The 'Wealth Divergence (r > g)' simulation: sliders for return on capital (7%), economic growth (2%), initial wealth and time horizon, scenario presets by country and era, and a question asking you to predict the result before you see it.
Move r > g yourself
Captured 2026-10-16 from the live web reader at phone size.

"Ask the book" takes a question about the chapter you are reading. The answer comes from that chapter's text. It needs you to sign in, so there is no screen of it here.

It is for anyone who has got what they wanted and wondered why it wasn't enough.

What is free and what costs money

The whole text is free, with no ads and no account, in the browser and in the apps. The English narration of the preface, the introduction, the first chapter ("The World Is Behaving Strangely"), the epilogue and the appendices is free too.

Lifetime Access is a one-time purchase. It adds the full narration, offline downloads, and reading progress synced across your devices. The App Store lists it at $6.99 in the US and ¥1,100 in Japan. You can also buy it on Google Play (sign-in required) or in the browser, and the price shows on the purchase screen.

"Ask the book" needs you to sign in. Your first 75 credits are free.

Some things aren't there yet. Narration is English only for now. If you read even one chapter and something is unclear, or a translation reads oddly, I'd like to hear about it.

See it in the exhibit hall