The aim of the paper is to give a short overview of the main findings related in the studies of V. K. Orfinskaya, Professor of Department of Psychopathology and Logopedics of A. I. Herzen Institute of Leningrad, devoted to alalia and aphasia. V. K. Orfinskaya was the first scholar in the history of aphasiology to undertake a comparative linguistic study of alalia and aphasia using an original method, based on observation of a speech disorder in the process of its overcoming, i.e. in the dynamics of rehabilitative logopedic work. The linguistic classification created a chance to single out speech disorder levels on the basis of the sequence of formation of linguistic systems in their ontogenesis. The first level includes disorders of phonetic differentiations, the second - inadequacy of the phonemic and morphological linguistic systems, between which the morphological one is more highly organized. The third level is expressed by the inefficiency of the significative function of the phonemic and morphological systems and emerges as a result of disruption of interanalyzer connections causing a switch-off of speech analyzers. According to the author, the fourth level includes speech disorders caused by disintegration or underdevelopment of generalizations lying at the basis of linguistic notions emerging as a consequence of immaturity of speech analyzers (apraxico-agnostic forms of aphasia and alalia). The lower the level of disorder, the more severe speech pathology, and the harder it is to overcome it. The process of compensation for each linguistic system goes along stages of its development in the ontogenesis. Rehabilitation work should follow the same route - i.e. first comes training of relatively elementary functions of the system, and then follow the more complicated ones. Thus, V. K. Orfinskaya created a logical conception embracing the mechanisms of various forms of disintegration of speech and pathology of its development, the ways of diagnostics, and the program and techniques of differential rehabilitation activity. Ключевые слова: афазия; алалия; логопедия; нарушения речи; расстройства речи; фонематические системы; экспрессивная речь; персеверация фонем; двигательные анализаторы; лингвистический анализ; научные труды. Keywords: aphasia; alalia; logopedics; speech disorders; speech impairments; phonemic systems; expressive speech; perseverance of phonemes; motor analyzers; linguistic analysis; scientific works. Сведения об авторе: Трауготт Наталия Николаевна (1904-1994), нейрофизиолог, доктор медицинских наук (1964), профессор. С 1956 г. Н. Н. Трауготт возглавляла лабораторию патологии высшей нервной деятельности Института эволюционной физиологии им. И. М. Сеченова. Во время первой публикации работы (1983) была сотрудником государственного научно-исследовательского психоневрологического института им. В. М. Бехтерева. About the author: Traugott Nataliya Nikolaevna (1904-1994), Neurophysiologist, Doctor of Medicine (1964), Professor. Since 1956, N. N. Traugott headed the laboratory of pathology of the higher nervous activity of I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry. At the time of the first publication of the paper (1983), she worked at St. Petersburg Bekhterev Psychoneurological Research Institute.