'Franco De Masi is well known for his psychoanalytic work with patients suffering psychotic illnesses. In this book, he addresses the human vulnerability to psychosis, but the modest title of his book belies the depth of its investigations and conclusions. De Masi invites the reader into a thoughtful, systematic exploration of many aspects of the complex problems associated with psychotic illnesses: its ontogenesis and the emotional crises that lead to the dominance of psychotic thinking, the function of psychosis with regard to reality, its eruption or progression (depending upon the type of psychosis involved) and, crucially, the difficult and painstaking task of treatment. This latter theme is explored in considerable detail and is perhaps the most telling message of this book. Example after example of de Masi's engagement with patients illuminates his central objective - the gradual disinvestment by the patient of psychic energy allocated to ostensibly protective, but ultimately self-destructive, psychotic constructions and a re-investment in neurotic or more normal psychic reality - a world the patient has had to largely forsake under the sway of delusion... This book is large in scope and substantial in content. It provides the clinician with important perspectives on the origins and development of delusions in psychosis and offers a new perspective regarding the radical differences between delusional and normal or neurotic thought, and how these differences come about. It moves our thinking forward in an area that has too often been neglected, and for this we need to be grateful.'- Paul Williams, from the Introduction.