For many ancient cultures in India, China and the Middle East, religion was not about worshipping a Supernatural Intelligence but precisely the attempt to appreciate the limits of our understanding and language. As the theologian Herbert McCabe declared: 'To assert the existence of God is to claim that there is an unanswered question about the universe'. Science has pushed hard at those limits. So is there anything left? Will there be anything that will always be beyond the limit? Does McCabe's God exist?To try to answer this ancient conundrum du Sautoy considers a wide range of scientific and mathematical questions. These mainly centre on physics and cosmology but he also looks at how consciousness arises from brain activity and at the foundations of mathematics. Most of this, apart perhaps from the mathematics, will probably be fairly familiar to most readers of popular science books, so what is mostly of interest is learning what du Sautoy himself makes of it all. At the end of his explorations he arrives at conclusions that are somewhat different from what he expected to find at the outset. Some problems that he thought would be unknowable, such as whether the universe is finite or infinite, may turn out to be solvable. Whether time existed before the Big Bang may also be something we can approach theoretically and perhaps even on the basis of evidence.
On the other hand there are questions in physics that we may not be able to resolve. We have found that the atom is not, as its name implies, indivisible but is made up of smaller components. But have we reached bedrock or is there more to find?
Every generation thought they'd hit the indivisible only for matter to fall apart into smaller pieces. How can we ever know that the current building blocks of the universe—electrons, quarks, neutrinos—aren't as divisible as all the other particles we've hit as we've peeled the onion of reality?And then there is consciousness and free will, and how they relate to brain activity. Is this insoluble or will it turn out to be a badly posed question?
Will it be answered with a strategy similar to that used by scientists to pin down the essence of life? There was no élan vital, just a set of biological processes that means a collection of molecules has life. Or will the problem of consciousness remain something that can never be understood because we are stuck inside our own consciousness and can never get inside another's?In fact, the notion that we are stuck within the system underlies much of the discussion in the book. It even emerges in mathematics, as a result of Gödel's incompleteness theorem. And it turns up in another form as limitations due to our use of language, as du Sautoy brings out in an illuminating comment on the paradoxes of quantum physics.
Understanding quantum physics is such a problem because the only language that helps us navigate the ideas is mathematics. Try to translate mathematics into the language of everyday experience and we create absurdities that make quantum physics challenging. So the unknowability of position and momentum isn't really a genuine unknowable. Rather, it is a failure of translation from mathematics to natural language.At the end of his book du Sautoy finds that the safest bet may be to acknowledge that we cannot say for sure what it is we cannot know. This agnostic conclusion leads him to wonder whether he should still call himself an atheist. His initial view was to dismiss religion as preaching the 'God of the gaps'. So if there are, in principle, no gaps—if there is nothing we cannot know—there is no room for God. But since he no longer believes that there is nothing we cannot know, perhaps he has proved that God exists!
But what sort of God?
My statement about being an atheist is really just a response to the rather impoverished version of God offered by most religions and cultures. I reject the existence of a supernatural intelligence that intervenes in the evolution of the universe. This is a rejection of the God that people assign strange properties to—such as compassion, wisdom, love—which make no sense when it comes to the idea that I am exploring.As he remarks, this conclusion will please neither militant atheists nor religious believers. It is quite close to the deism (as opposed to theism) of Enlightenment thinkers such as Thomas Jefferson, and probably even closer to the view of Baruch Spinoza, whose name, rather surprisingly, does not figure in the index.
For a similarly agnostic approach based on the impossibility of our having full knowledge of reality see Ultimate Questions, by Bryan Magee.