The book is devoted to the methodology of psychopathological analysis, the systematics of illusory and hallucinatory phenomena encountered in mental disorders, as well as outside the disease in their statics and dynamics. Classification of these phenomena is presented. A brief description of the criteria for clinical assessment is given, the definition of the main types of illusions and hallucinations is specified, controversial issues of the doctrine of hallucinations are dealt with. The book is intended for psychiatrists.