In this groundbreaking book, neuroscientist Giulio Tononi presents his Integrated Information Theory (IIT) to explain consciousness. Through a creative dialogue format inspired by Galileo, he explores what consciousness is and how it emerges from the brain's complex structure. Tononi argues that consciousness is a fundamental property of the universe, quantified by a measure called 'Phi' (Φ), representing the level of integrated information in a system. This work masterfully blends science, philosophy, and narrative to tackle one of life's greatest mysteries.