Political theory has mainly considered political deception as induced either by lies and manipulation or as the unintended consequence of misperceptions and illusions. This work aims to show that the misperception of reality, under psychological and emotional pressure, is often driven by the desire to believe what one wishes to be the case even if a dispassionate consideration would lead to the opposite conclusion. The phenomenon of self-deception has sometimes been hinted at in political analysis but rarely pursued and analyzed properly. This book is in two parts: in the first, the philosophy of self-deception will be considered in order to provide a clear definition and an adequate account of the phenomenon, and to explore the issue of responsibility for one’s self-deception. In the second part of the book, self-deception will be applied to political analysis.