The Beginning of Infinity: Explanations that Transform The World (Allen Lane Science) [Hardcover]

It has been 14 years since the publication of *The Fabric of Reality* and here at last is the sequel!

Within a few hours reading I'm confronted by explanations of how Occam's Razor is a misconception and how the biosphere cannot sustain human life. So, wow, I'm hooked!

Chapter 6: "The Jump to Universality" alone is worth the price of the book. It explains how many systems of symbolic representation, such as written characters, numerals and the genetic code evolve slowly and steadily before wandering into universal domains with corresponding huge leaps of expressive power.

The theme of *The Beginning of Infinity* is how the search for hard-to-vary explanations is the source of all progress in science and in the rest of human affairs, and that this progress may continue indefinitely, since all problems are soluble. But it can only do so if we choose to make it happen, in part by acknowledging that problems are inevitable and that 'all evils are caused by insufficient knowledge' (Deutsch's 'Principle of Optimism'). This makes human beings precious and of central importance in the scheme of the things, including cosmological physics.

There is a lot of material here, in 18 Chapters, because Deutsch is most concerned with ideas which have 'reach', including reach into diverse disciplines such as aesthetics, morality and political theory.

My guess is that some if not many readers will be put off by this breadth, considering it arrogant for an academic to write authoritatively outside his home fields of physics and the philosophy of science. However, uniquely, this very book explains both why fundamental explanations do this and why such a response might occur (namely, through the operation of *anti-rational memes*)

Deutsch's development (in Chapters 15,16) of Dawkins and Blackmores' theory of memes is seminal stuff, and takes us into politics and sociology. The classification of memes into rational/anti-rational is novel and fascinating. Together with a careful investigation into the logic of the transition from pre-humans to humans, it leads to yet another extraordinary claim: that human creativity evolved because it promoted, not innovation, but *conformity* to the norms of static societies.

The style of the book is quite convoluted in places. I think people who haven't read *Fabric* would be well advised to do so first (mainly to make sure they understand Popper's epistemology), and also to watch Deutsch's two TED talks online (e.g. 'What is our place in the cosmos?' corresponds roughly to Chapter 3: "The Spark"). Although the concepts of quanta and the fungibility of particles did seem like simple and useful entry points into the multiverse and quantum mechanics (QM), I must confess I found it pretty hard going and re-reads of Chapter 11 are probably called for.

There is a humorous dialogue between Socrates and a god (I'll leave you to discover which god and what the circumstances are); the young Plato is gently mocked. There are some great criticisms of 'explanationless science' and other bad philosophy, such as the equivocations and evasions introduced in the early days of QM (to avoid thinking about what it says is really out there).

I hugely enjoyed this book. I didn't so much read it; it read me. We need good philosophy to guide us in science and everywhere else in life.

"The Beginning of Infinity" by David Deutsch (BoI) is a great book that explores a range of important issues in physics, maths, explanations, the theory of knowledge (epistemology) and political and moral philosophy. This may make BoI sound somewhat daunting and impractical to many people. Who needs that sort of high flown stuff? However, one of the ideas in BoI is that explanation is important and that good explanations seem obvious and expand your horizons at the same time, and every explanation in BoI illustrates this point. In addition, the author explains himself very clearly, so there isn't a steep hill to climb to understand the explanations he gives. BoI is also entertaining and often quite witty. BoI will also repay repeated reading because there are a lot of ideas in it.

I'll give a brief sketch of some of the ideas you can expect to find in BoI. The first idea that I would emphasize is that explanation is central to living a rational and satisfying life. Good explanations are well adapted to solving problems - for example, the theory that the Earth orbits the sun is well adapted to explaining the seasons.

The next is that problems are inevitable because we will certainly make mistakes, and they are soluble because those mistakes can be fixed. The author explains that any way of changing the world that is not forbidden by the laws of physics is allowed. If there was some problem that we could never possibly solve, e.g. - some mathematical proofs can't be proven, then that would in itself be a fact about the laws of physics. Some people might say that parts of the world could be incomprehensible but that's a retrograde step back into the anti-rational worldview that says that something like God designed the universe for his own mysterious purposes that we can't comprehend. David Deutsch applies this perspective in interesting ways to a wide range of issues from the anthropic principle to political philosophy and global warming. He also explains why we should be optimistic: our knowledge is finite, our ignorance is infinite and the world is comprehensible so we may continue to make progress indefinitely if we choose to do so.

There is also stuff in BoI about irrational ideas that manage to propagate themselves in people despite the fact that they block progress. Deutsch explains some ideas about how to spot these ideas in yourself, so this book is not just theoretically interesting it can help you in your personal life.

Other interesting parts of BoI include a chapter in which the author explains quantum physics in english with no equations. There is a chapter about infinity in maths and physics - again with no equations. Another chapter explains why aesthetics is objective, still another discusses the reality of abstractions. I'm going to stop now, not because I've run out of things I could say about the book, but because I could write all day about it. And that's one reason why the title of this book is fitting - it is a beginning of infinity because it's a book you'll want to think about all the time after you've finished reading it.

The same is true of the David Deutsch's previous book The Fabric of Reality: Towards a Theory of Everything, which everybody should also read.

It takes disparate topics and unites them in one powerful worldview. Topics range from physics and philosophy to voting systems and alphabets to optimism and objective aesthetics to evolution and creationism, and even morality. Each topic has enlightening individual analysis, but even better than that is the worldview behind the analysis, which comes out as one reads the entire book. The Beginning of Infinity is about a way of thinking. It is the most rational way of thinking ever to be explained.

You might think that David Deutsch is a genius (and he is) and that therefore his way of thinking won't work for you. That is not the case. His worldview can help anyone with any topic. It's not equally useful for all fields -- it fairs better with important topics -- but it always has a surprisingly large amount of relevance and use. And unlike many philosophers who want to sound impressive, Deutsch has made a concerted effort to write clearly and accessibly. This isn't a book written only for the initiated.

I've identified three main themes which I think best describe the most important message of the book.

The first theme is the titular one. Like Deutsch's previous book, chapters conclude with short summaries and terminology sections. But he's got a new section too: the meanings of the beginning of infinity encountered in the previous chapter. So what kind of infinity is Deutsch concerned with? Primarily progress. Humans are capable of an infinite amount of progress. We can improve things without limit, and learn without limit. This covers not just material improvement but also moral improvement. Some impressive types of potential progress discussed in the book include building space stations in deep space, immortality and creating a more open, tolerant and free society.

The second theme, which is the most fundamental, is epistemological. Epistemology is the study of knowledge. Deutsch discusses issues like how we learn, and the correct and effective ways of thinking. Insights from this field, such as how to be rational, the inevitability of mistakes and the need to be able to correct mistakes (rather than rely on avoiding them all in the first place) underlie everything else. For example, Deutsch proposes an epistemological principle as the most important moral idea. I won't keep you in suspense: it is the moral imperative not to destroy the means of correcting mistakes. But if you want to fully understand what this means you'll have to read the book!

The third theme, which is prevalent without usually being stated explicitly, is liberalism in its original, not left-wing, meaning. Liberalism draws on the other two themes. It is about organizing society to allow for human progress, rational lifestyles, knowledge creation, and the correcting of mistakes. To do this its biggest principle is not to approach conflicts and disagreements with the use of force because force does not discover the truth of the matter and everyone should seek to figure out the truth and do that rather than taking a might makes right approach. Liberalism is the philosophy of open societies and the only one capable of supporting unlimited progress. In contrast to open societies, Deutsch also discusses static societies which do not make progress. He explains how they will eventually fail and cease to exist because there are always new and unforeseeable problems which they cannot adapt to. Only a liberal society which moves forward has the means of dealing with the unknown problems the future holds.

There is a lot to love about The Beginning of Infinity. If you are narrowly interested in physics you should read it for the chapter explaining what the multiverse is like -- and when you do you may also be challenged by the chapter on bad philosophies of science and intrigued by the chapter on the reality of abstractions. If you are only interested in math and computation, you'll want to read the chapter on AI, but you'll also enjoy the chapter about the concept of infinity. If you're an artist you'll appreciate the discussion of the beauty of flowers, and the wit of the Socratic dialog. Whatever the case may be, the philosophy running throughout has universal interest.