At the end of the 19th century Sigmund Freud discovered that our acts and choices are not only decisions of our consciousness, but that they are also deeply determined by our unconscious (the so-called "Freudian unconscious"). During a long correspondence between them (1932-1958) Wolfgang Pauli and Carl Gustav Jung speculated that the unconscious could be a quantum system. This book is addressed both to all those interested in the new developments...