This important work provides an account of the philosophical foundations of quantum theory that should become a classic text for scientists and nonscientists alike. Hughes offers the first detailed and accessible analysis of the Hilbert-space models used in quantum theory and explains why they are so successful. He goes on to show how the very suitability of Hilbert spaces for modeling the quantum world gives rise to deep problems of interpretation, and makes suggestions about how they can be overcome.The power and elegance of the quantum-mechanical arguments are excellently portrayed and the reader&could not help being impressed by the sheer intellectual beauty of the subject.[This book] complements the material covered in standard textbooks on quantum theory, in which the issue of interpretation of the theory is too often neglected.Hughes has written the best self-contained introduction to the foundations of quantum mechanics yet to appear& Hughes is clearly a gifted teacher, and a casual look at the book may suggest that it is primarily a textbook. In fact, a definitive interpretive perspective is developed throughout the book.A formidable and intelligent account of the (partial) Hilbert-space formalization of quantum mechanics and the inevitable philosophical ambiguities that result& A marvelous book.R.I.G Hughes offers the first detailed and accessible analysis of the Hilbert-space models used in quantum theory and explains why they are so successful. He goes on to show how the very suitability of Hilbert spaces for modeling the quantum world gives rise to deep problems of interpretation and makes suggestions about how they can be overcome.