"The concept of quantum physics led Einstein to state that 'God does not play dice'. The difficulty he, and others, had with quantum physics was the great conceptual leap it requires us to make from our conventional ways of thinking about the physical world. Rae's introductory exploration into this area has been hailed as a 'masterpiece of clarity' and is an engaging guide to the theories on offer." This new edition has been revised throughout to take account of developments in this field over the past fifteen years, including the idea of 'consistent histories' to which a completely new chapter is devoted.