I agree, there are a lot of ifs in this book, with a crucial one on p. 93: 'If quantum effects prevent the formation of singularities ... then time does not end in the centre of black holes, but continues into some new region of space-time.'

Smolin explains that behind the central principles of relativity and quantum mechanics lies the essential fact that 'All properties of things in the world are only aspects of relations among real things, so that they may be decribed without reference to any absolute background structures.' (p.259)
For Smolin, the future of physics is to find a solution for the tension between the atomist description of elementary particles, and their relational use in the gauge principle. He believes that string theory is part of the solution.

Smolin's point of view is partly shared by the late Nobel Prize winner Ilya Prigogine in his difficult book 'The End of Certainty'.

Even if his theory is falsified, this book is a real bargain, because it contains magnificently clear (a real bonus) explanations of the 4 basic forces in physics, the gauge principle, symmetry breaking, quantum mechanics, gravity, the second law of thermodynamics, the theory of natural selection, Leibniz's philosophy, the reason why mathematical and logical truths may be eternal ... I could go on.
Into the bargain, it contains a deadly attack on determinism and a very polite but definitive refutation of the anthropic principle.

A great book by a true and free humanist.

That said, there is plenty if interesting stuff to ponder here. Perhaps because Smolin is trying to appeal to a popular audience, I sometimes found his explanations lacking in depth - for example, the assertion that certain parameters that determine the composition of the universe and its hospitability to life are fine-tuned to an accuracy of one part in 10 to the 60th power. Not being a physicist or mathematician, I can only take what Mr Smolin says at face value. I'm also not sure about black holes being the generators of new universes - it strikes me as an idea that can never betested or proved. Perhaps the development of the grand theory that Mr Smolin ultimately hopes for will provide further support for his cosmological natural selection, through testing of new mathematical models. But I still feel that much of what he is saying will always remain beyond the scope of science, and to a large degree must be taken on faith. But I take my hat off to him for thinking so big.