The book by the famous Russian philosopher and psychologist Vadim Rudnev is dedicated to understanding issues related to the construction of the logic of delusional ideas from the standpoint of the philosophy of ordinary language and psychosemiotics, an interdisciplinary approach that the author of the book has long been developing in his research. The author introduces a number of new concepts, such as unconscious narration, consensual delusion and genuine delirium. Unconscious narration is a narrative that unfolds outside of the consciousness of its author. Consensual nonsense is the reality in which we live. Genuine delirium is not just the delirium of a schizophrenic, but some special and, as a rule, creative state of the human psyche. The book is written in a lively, fascinating language. It will be interesting and useful not only to psychologists, philosophers and cultural experts, but also to all readers for whom the issues of the development of human intelligence are relevant.