This book is now my favorite book on quantum mechanics. The initial approach looks a bit like Sakurai's book, being less technical. I read this book without reading volume 1 on classical mechanics. However, this did not impair reading. Volume 1 is only remembered in the relationship between the commutators of quantum mechanics and the Poisson brackets of classical mechanics. I recommend this book to anyone who wanted to start studying in this area. I just missed a section on Bell's theorem in the quantum entanglement chapters.