Notes on 21 Lessons for the 21st Century

These are notes on ideas and concepts I found interesting — not a comprehensive summary of the book. Buy the book

Unlike Sapiens and (to a lesser extend) Homo Deus, 21 Lessons feels like a collection of good essays with only a handful of truly insightful passages. Those sections that did jump out did make me think enough to go circle back for some notes, though.

The nuggets that interest you may be different to those that stuck out to me, but here’s a few passages that were insightful to me (emphasis mine):


At present we are not doing much in the way of research into human consciousness and ways to develop it. We are researching and developing human abilities mainly according to the immediate needs of the economic and political system, rather than according to our own long-term needs as conscious beings.

In this, humans are similar to other domesticated animals. We have bred docile cows that produce enormous amounts of milk but are otherwise far inferior to their wild ancestors. They are less agile, less curious, and less resourceful. We are now creating tame humans that produce enormous amounts of data and function as very efficient chips in a huge data processing mechanism, but these data cows hardly maximize the human potential. Indeed, we have no idea what our full human potential is, because we know so little about the human mind.

And yet we don’t invest much in exploring the human mind, instead focusing on increasing the speed of our internet connections and the efficiency of our Big Data algorithms. If we are not careful, we will end up with downgraded humans misusing upgraded computers to wreak havoc on themselves and on the world.


Humans have bodies. During the last century technology has been distancing us from our bodies. We have been losing our ability to pay attention to what we smell and taste. Instead we are absorbed in our smartphones and computers.

We are more interested in what is happening in cyberspace than in what is happening down the street. It is easier than ever to talk to our cousin in Switzerland, but it is harder to talk to my husband over breakfast, because we constantly looks at his smartphone instead of me.


Religion is very similar to fake news. When a thousand people believe some made up story for one month, that’s fake news. When a billion people believe it for a thousand years, that’s a religion, and we are admonished not to call it ‘fake news’ in order not to hurt the feelings of the faithful (or incur their wrath)


As the rate of technological and societal change continues to increase, how can people broadly, and younger generations specifically, best prepare?

You will need a lot of mental flexibility and great reserves of emotional balance. You will have to repeatedly let go of some of what you know best, and learn to feel at home with the unknown. Unfortunately, teaching kids to embrace the unknown and while maintaining their mental balance is far more difficult than teaching them an equation in physics or the causes of the first world war.




Founder of DoubleUp (, co-founder of Supercast ( Admirer of simplicity, fan of excess. Sharing notes at

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Aidan Hornsby

Aidan Hornsby

Founder of DoubleUp (, co-founder of Supercast ( Admirer of simplicity, fan of excess. Sharing notes at

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