I cannot say that I read this book “well” or carefully. It is the first book that I have read cover to cover in a while, the last one probably being The Diving Bell and the Butterfly by Jean-Dominique Bauby, last year. I rushed forwards and forwards, not reflecting on what I had just read, and now that I am at the end of it I realise I only caught fragments. I got the gist, but most of the detail has already slipped away. The detail was never firmly etched in my mind, it just brushed across my consciousness for a moment and then was gone.

Still, what did I get from it? What can be said about a book that so many people have raved about? I did not read carefully enough to understand Deutsch’s arguments about the multiverse or the anthropic principle, but I did get his incredible, maybe infinite optimism, that comes from his belief that all problems are soluble with the appropriate requisite knowledge. Deutsch easily and calmly extrapolates from the fact that humans are universal constructors and that the universe is infinitely comprehensible to us given appropriate computational and memory resources, to the idea that it is possible to create solar system size supercomputers made from the gas found in interstellar space.

I think some of his pontificating on the nature of prehistoric societies, characterising them as simply static without revealing any further interest in how they might have worked, is a bit naive. Deutsch does seem to be too rapidly (for my liking) dismissive of pre-Enlightenment and not-quite-Enlightenment cultural traditions. Maybe that’s just not his interest area. However, he does have the right take on Jared Diamond, that his biogeographic explanation for how different parts of the world developed is a bad explanation. Why didn’t the more native Americans domesticate llamas? Because there was a desert in the way. That’s not an explanation. The real answer is another question. Why didn’t they develop the cultural technology to solve the problem of the desert (people did cross it and sail round it, so the physical technology was there)? Why couldn’t they understand the world well enough to improve it in this regard? Or maybe, did they even want to improve it in this regard? Most people at most times want to make their lives easier and more comfortable, even when their cultural beliefs are otherwise very hard and stoic, so if they didn’t want to make their lives easier through better explanations, why didn’t they. Deutsch half answers these questions by blanketly referring to these cultures as static societies but there are a lot of anthropoligical questions to ask here.

It was a very interesting book. I was expecting it to be a lot heavier but it was surprisingly readable. I would recommend it to anyone interested in understanding where scientific ideas actually come from, how science progresses, and how creative thinking and explanation creating in general ,progresses. Whether at the scale of an individual grappling with individual problems, or at the scale of humanity as a whole developing this new post-Enlightenment world together, problems are soluble. All we need is to create the right knowledge. This is incredible optimistic in an age still so strongly pessimistic.