There are a lot of popular science books on quantum theory but this one is different in that its aim is to question what's meant by reality. Manjit Kumar achieves this objective admirably. He also provides what I've found to be the best and most coherent account of the history of the development of quantum theory that I've read, managing, at the same time, to bring alive many of the key physicists and mathematicians involved, and not just Neils Bohr and Albert Einstein who are in the book's title. He also succeeded in explaining many aspects of quantum theory without resorting to mathematics, which is no mean feat. An exception was Bell's Inequality Theorem but I doubt that anyone could explain that in a non-mathematical way - despite having read several accounts by different authors I still have little idea of why this theory should tell us anything about hidden variables, but evidently it does. Whilst the subject of reality forms the main theme of the book, it's past the half way point before this topic is discussed in any serious way. But then Manjit examines the concept very thoroughly, focussing on the Copenhagen interpretation along with Einstein's objections to this interpretation, based on his belief that quantum theory is incomplete and that probability and non-locality must have some underlying explanation that is still to be discovered. My only criticism is that I feel the book could have been shorter, perhaps my omitting some of the finer detail when it came to history or by cutting out some of the views expressed by "lesser" scientists. There is quite a lot of repetition but, from my perspective, I found that helpful in reinforcing many of the points raised. However, a reader more familiar with the area might find the repetition irritating.