Nonfiction book about languages and the effect on culture, or culture and the effect on languages. Depends on how you read it and what you think about it, really. Deutscher discusses at length various linguistic theories and how they have evolved over time as the scientific side of intellectual curiosity gained prominence and became more refined with the use of experiments and scientific method that weeded out human fallacies. (Or tried to, anyway!)
He starts and ends with color - the peculiarities of the vocabulary of color in Homer's Odyssey at the beginning of the book and the testing of color differentiation across various languages native speakers at the end of the book - and covers several other topics along the way. It is long and overly confusing at times because the author can't resist making a tangential joke that doesn't really add to your understanding of the subject; in fact, I'm inclined to believe it's more to do with page count requirements. Comprehensive reading of this book may require a graduate-level vocabulary and the high-brow humor may fly over the head of someone not looking for it. He does bring to light several experiments/studies that the general public would not be aware of and explains the reasons for their importance in laymen's terms, or makes an attempt at doing so at least.
It took me three-quarters of a year to read this book because I got stuck in the middle and was bored. I say this as person strongly interested in linguistics but not involved in any particular career related to the field, so this may be more geared to those with a professional rather than a casual interest in languages.