Book excerpt: In this 10,000-word essay, written to complement Iain McGilchrist's acclaimed The Master and His Emissary, the author asks why - despite the vast increase in material well-being - people are less happy today than they were half a century ago, and suggests that the division between the two hemispheres of the brain has a critical effect on how we see and understand the world around us. In particular, McGilchrist suggests, the left hemisphere's obsession with reducing everything it sees to the level of minute, mechanistic detail is robbing modern society of the ability to understand and appreciate deeper human values. Accessible to readers who haven't yet read The Master and His Emissary as well as those who have, this is a fascinating, immensely thought-provoking essay that delves to the very heart of what it means to be human.