David Deutsch is not short of self-confidence. In the bibliography of this mind-stretching book on the philosophy of science, under the heading "Everyone should read these", he's listed two of his own publications alongside the work of Karl Popper and Richard Dawkins. Within 50 pages of The Beginning of Infinity, he's taken issue with statements by Dawkins, Stephen Hawking, the Nobel Prize-winning physicist Richard Feynman and the world's most famous inventor, Thomas Edison. Towards the end of the book, he even has a pop at David Attenborough, which is a bit like attacking a baby panda with a bread knife. Intellectually speaking, that is.
To be fair to Deutsch, he is clearly a wide-ranging and deep thinker, but while there are some real eye-opening arguments put forward, there are also long passages of almost impenetrable waffle, and the author certainly doesn't possess Hawking's or Dawkins's knack for clear and concise prose.
Deutsch's task is made more onerous by the breadth of his subject matter. He is a quantum physicist by trade, and uses his area of expertise as a jumping off point to examine the nature of knowledge and explanations, as well as the implications of his conclusions for humankind, not only in terms of science and mathematics but also culturally, morally and aesthetically.
It's a monumental undertaking that he doesn't pull off entirely convincingly, but the central tenets of his arguments seem sound, at least to this layperson with a PhD in nuclear physics. Deutsch argues that explanations of the physical universe have a fundamental place within it, the upshot of which is that those who seek explanations – sentient beings such as us humans – are the most important entities in the universe.
On the surface, this seems an anthropic argument that gives us more importance than we deserve in the cosmic scheme of things, but Deutsch is ultra-rationalist in his approach, and not prone to lazy, human-centric modes of thought. Instead, he argues that the extent of all possible knowledge is essentially unbounded (thus the title of the book), and he makes a decent case for this being an extremely optimistic state of affairs.
If it all sounds a trifle heavy going, well, it is at times. Deutsch is clearly aware that it's a difficult topic, and each chapter comes with an explanation of terminology used and a summary. But even so, he can still lapse into the kind of language that reads like a spoof of philosophical discourse. This from the summary of Chapter Five: "Abstract entities are real, and can play a role in causing physical phenomena. Causation itself is such an abstraction."
In general, Deutsch is much better on his home turf of physics than in other fields. His examination of the multiverse theory of quantum physics is great. But when he tries to apply his ideas to aesthetics, cultural creativity and moral philosophy, he seems on shakier ground and is less commanding as a result.