Christian Perring

This dissertation is a philosophical investigation of irrationality. The aim is to provide a conceptual basis for understanding various forms of irrationality, such as psychosis, neurosis, self-deception, repression, and weak-willed behavior. There are six main chapters, focusing on different phenomena, and touching on several fields of inquiry, including moral psychology, value theory, philosophy of mind, philosophy of language, philosophy of science and psychoanalytic theory. The first two chapters are broad in scope, discussing the relation of philosophy to clinical psychology, and the very possibility of the existence of irrationality. The subsequent four chapters explore the particular topics of the disunity of self, unconscious mental states, self-deception, and weakness of will. There is no single overriding thesis being argued for here, but the general theme is that it is possible to understand irrationality in detail, and that the forms of irrationality that we are capable of understanding include extreme ones that many thinkers have deemed conceptually or logically impossible. Chapter One argues for the importance of the interrelation of philosophy and clinical psychology. Chapter Two argues against the necessity of charitable assumptions of rationality in interpreting the language or behavior of others. Chapter Three discusses the various ways in which the disunity of persons have been conceptualized, and argues that homuncularism often confuses different levels of talking about people. Chapter Four argues for a strong ontology of unconscious mental states and processes, giving them equal status to conscious mentality. Chapter Five argues against several so-called 'paradoxes of self-deception' and clears the way for the possibility of intentional self-deception. Finally, in Chapter Six a standard conception of the distinction between valuing and desiring is examined and found wanting. A new model of the nature of valuing is proposed, drawing on Gestalt psychology. On this view, most weak-willed behavior involves not a divergence between what is desired and what is valued at the time, but rather a change in the person's values. If there are occasions where what is valued differs from what is desired, they are rare and demand a special explanation