Ivan Sechenov

SECHEROV, Ivan Mikhailovich (1829–1905), an outstanding scientist, founder of the school of Russian physiologists; born into the family of a landowner in the village of Teply Stan, former Simbirsk Governorate (Middle Volga Region); at the age of 14, he entered the lower department of the Main Engineering Technical School, received his first officer rank upon moving to the upper department, but due to the hostile attitude of the head of the school, he did not fully complete the course and was discharged from it in 1848 for active military service in a sapper battalion in Kiev. At the beginning of 1850, Sechenov resigned and in the autumn of the same year entered the medical faculty of Moscow University, from which he graduated in 1856, having passed the examination directly for the degree of Doctor. In the same year, having received a small inheritance, Sechenov went abroad, where he worked in the laboratories of Hoppe-Seyler and Du Bois-Reymond in Berlin, Funk in Leipzig, Ludwig in Vienna, Bunsen and Helmholtz in Heidelberg. Having received an invitation to the position of assistant professor at the Medico-Surgical Academy, Sechenov arrived in St. Petersburg at the beginning of 1860, defended his dissertation for the degree of Doctor of Medicine written abroad, Materials for the Future Physiology of Alcoholic Intoxication, and from March until the holidays gave a course of lectures On Animal Electricity, which upon publication was awarded a prize by the Academy of Sciences. Sechenov remained at the Medico-Surgical Academy until 1870, when, already a full professor, he resigned due to a disagreement with the majority of the Academy's conference, which balloted down I. I. Mechnikov, whose candidacy to fill the chair of zoology was proposed by Sechenov. In the same year, Sechenov was elected by the physics and mathematics faculty and the council of the University of Odessa (Novorossiysk) to the chair of physiology, but confirmation by the ministry followed almost a year later and then only thanks to the guarantee of the trustee of the Odessa educational district. In 1876, at the invitation of the physics and mathematics faculty of St. Petersburg University, Sechenov moved from Odessa back to St. Petersburg. In 1888, under the influence of a depressed mood due to the fate of his absorptiometric research, he resigned and in 1889 joined the privat-docents of the medical faculty of Moscow University. In 1891, upon the death of Prof. Sheremetyevsky, he took up the chair of physiology at Moscow University at the invitation of the medical faculty. In 1901, "to clear the path for young forces," he renounced his salaried position and lecturing at the university. In the autumn of 1903, he accepted an offer to teach a course in anatomy and physiology at the Prechistenka Courses for workers. The course was not completed, because in February 1904 the director of public schools did not approve Sechenov "in the position of a teacher of the Prechistenka Classes." Having retained his workplace in the laboratory upon resignation, Sechenov continued to work in it until his death. During his nearly half-century of scientific activity (1858–1905), Sechenov worked in the laboratory predominantly on two issues: 1) blood gases in connection with their respiratory exchange and 2) the phenomena of inhibition of movements, their stopping (Hemmungserscheinungen). He began to study the first of these questions in 1857 in Ludwig's laboratory, studying the composition of the blood gases of an intoxicated animal for his dissertation. Convinced of the imperfection of the existing methodology for obtaining gases from blood, Sechenov proposed for this purpose a mercury pump with a renewable vacuum ("Beiträge zur Pneumatologie d. Blutes", Sitzungsber. d. Wien. Akad., 1858), thereby providing a method for obtaining all gases dissolved in blood without residue and thus their quantitative determination. Thanks to this, the doctrine of blood gases was placed on a firm footing, and Sechenov's principle invariably remains in the design of all modifications of blood pumps up to modern ones inclusive. Sechenov returned to the study of blood gases again in the early 1870s in Odessa, undertaking a systematic study of the relation of various constituents of blood to carbonic acid by the absorptiometric method, as more fruitful in the detailed study of the state of gas in a liquid. For this purpose, he set up his original absorptiometer, work with which continued with greater or lesser interruptions for about 20 years and proved: 1) weak chemical absorption (dependent on pressure) of carbonic acid by blood serum (consequently also plasma); 2) the same absorption by hemoglobin; and 3) the impossibility of explaining (as was thought previously) the relation of serum to carbonic acid by the sodium carbonate contained in the latter. These results, which have long since entered physiology textbooks, showed that blood corpuscles participate in respiratory exchange (CO₂) by 1/3 and plasma by 2/3, and that the release of CO₂ from blood is an act fully corresponding to the diffusion of a gas dissolved in a liquid. Deepening his absorptiometric studies, Sechenov established a definite numerical law of the dependence of the absorption coefficients of CO₂ by salt solutions indifferent to it on the concentration of the solution and provided the basis for grouping salts according to their absorption capacity and absorptiometric affinity. In 1891, Sechenov showed the applicability of his law to the phenomenon of salt dissolution in solutions indifferent to them. Thus, this law acquired the significance of a general law for a very extensive class of phenomena, which was confirmed by the chemist A. A. Yakovkin. The final link in the methodology for studying gas exchange provided in Sechenov's works is the design, according to his idea, of a respiratory apparatus that makes it possible to quantitatively study gas exchange in humans both at rest and during movement of the test subject (jointly with M. N. Shaternikov—"Einportativer Atmungsapparat", Le physiologiste russe, vol. II, 1900). Finally, among Sechenov's works on respiration is a theoretical (mathematical) analysis of the question of how respiration is affected by the circumstance that blood absorbs only O₂ from alveolar air, and compensation for losses is made not with pure O₂, but with a mixture of it with nitrogen, i.e., atmospheric air. The question was analyzed for normal respiration, for breathing rarefied and compressed air, as well as for the case of a decrease in the percentage of O₂ or an increase in the percentage of CO₂ in the inhaled air. Extending the conclusions obtained for O₂ to the remaining components of alveolar air, Sechenov gave a theory of the composition of this air under various conditions of respiration, which retains its significance to the present time. By the second section of his works, the development of the doctrine of the inhibiting actions of the central nervous system, Sechenov earned worldwide fame at the very beginning of his activity, appearing as a pioneer in this completely untouched field prior to him. In 1863, he published in Russian, German, and French an investigation of the centers inhibiting reflected movements in the brain of a frog; this work established the presence in the middle parts of the frog's brain (lobi optici) of a physiological center for the inhibition of spinal cord reflexes. This center became known as the "Sechenov inhibiting center." In a number of subsequent works, Sechenov developed his doctrine of the specificity of inhibitory centers and further reinforced it with new systematic studies of the effects of stimulation of sensory nerves (St. Petersburg, 1868) and galvanic phenomena in the medulla oblongata (Vrach, 1882), which required extraordinary experimental skill. The question of central inhibition, a powerful impetus to the development of which was given by Sechenov, cannot be considered definitively resolved even to the present time, despite the fact that over the subsequent half-century a number of prominent researchers have dealt with it. In any case, Sechenov retains the indisputable priority of posing the question and laying the first paths to its resolution. The study of inhibiting centers served as an impetus for writing Sechenov's famous psycho-physiological treatise Reflexes of the Brain (Meditsinsky vestnik, nos. 47, 48, 1863), the main task of which is to prove the proposition that "all acts of conscious and unconscious life are reflexes in their mode of origin." This essay, being the brightest document of the militant materialist literature of the 1860s, on the one hand, met with an enthusiastic reception among the progressive part of society and became a desk book for studying youth, and on the other hand, provoked a negative attitude towards itself and the author from obscurants and ruling spheres. This book, as well as other articles following it in the same direction, caused a lively polemical literature around the issues of the materialist interpretation of psychological problems and the fight against idealism, in which many took part (see e.g.: Yurkevich, "The Language of Physiologists and Psychologists", Russky vestnik, 1862, nos. 4–6 and 8; Tarkhanov, "Shaky Points of Modern Realism", Biblioteka dlya chteniya, 1863, nos. 1–3; Pisarev, "On Yurkevich's Polemic with Chernyshevsky"). Upon the 2nd, expanded separate edition (1866) of the book, it was seized, under which status it remained for more than a year.

During this time, negotiations were underway between the Ministries of Internal Affairs and Justice regarding the destruction of the book and the prosecution of the author under the article punishing the authors of works that "have as their purpose the corruption of morals or are clearly contrary to morality and decency." These negotiations ended happily for the book and its author only because the prosecutor expressed doubt about the successful outcome of judicial prosecution, and the Minister of Justice managed to persuade the Minister of Internal Affairs not to make the trial into an advertisement for a book of "undeniably harmful direction." From then until the end of his days, Sechenov repeatedly experienced the disfavor of the authorities: the protracted failure to confirm him as a professor in Odessa (1870–1871), the refusal of the title of honored professor after 25 years of professorship (1885), the removal of Sechenov's candidacy for the Academy of Sciences (1886), and the ban on lecturing at the Prechistenka Courses for workers (1904). Yet the "undeniably harmful" ideas of Reflexes of the Brain undoubtedly lie at the foundation of the modern doctrine of higher nervous activity, so brilliantly developed by the luminary of Russian physiology, Academician Ivan Pavlov. Sechenov's psychological treatises and articles—"Who and How to Develop Psychology," "On the Elements of Visual Thinking," "The Doctrine of the Non-Freedom of the Will from a Practical Standpoint," "Impressions and Reality," "On Objective Thinking from a Physiological Point of View," and finally "Elements of Thought," collected in the 2nd volume of the posthumous edition of his works—represent a heritage of high scientific value. These articles by Sechenov touch upon the fundamental questions of the theory of knowledge, and in this field Sechenov provided models for the materialistic treatment of issues. Sechenov provided indisputable proof that the basis of the forms and movements we see lies outside us in reality, and that the similarity and difference of these forms and movements are the similarity and difference of reality (see Plekhanov's preface to the book: F. Engels, Ludwig Feuerbach, ed. by V. V. Adoratsky, Moscow, 1931). In his psychological views, Sechenov most of all adhered to Spencer's evolutionary doctrine, calling this doctrine "Darwinism in the sphere of mental phenomena." Having taken over the department and guided throughout his entire life by his motto "one can teach and learn only by working scientifically," Sechenov, wherever fate cast him, managed to unite students around himself and inspire them to scientific work. A number of prominent scientific figures emerged from his laboratories: Pashutinin, Voroshilova, Tarkhanov, Spiro, Verigo, Vvedensky, Salazkin, Kravkov, Khlopin, and others, and not only in the field of physiology, but also in related disciplines. The complete absence of any satisfactory textbooks and manuals on physiology compelled Sechenov to take up compiling them or translating foreign textbooks. His lecture courses On Animal Electricity (Moscow, 1862), Physiology of the Nervous System (Moscow, 1866), and Physiology of Nervous Centers (Moscow, 1891) are classical in our literature for the originality of their plan and presentation. An equally valuable contribution are his popular works on physiology, such as Physiological Essays (2nd ed., parts 1–2, Moscow–Petrograd, 1923). Deeply sympathetic to higher education for women, Sechenov was the first in Russia to admit women to his laboratory, and already in 1862 the works of his two female students, N. P. Suslova and M. A. Bokova (subsequently Sechenova), appeared in print. While in Petersburg, he lectured at the Bestuzhev Courses, and in Moscow at the collective classes of the Society of Female Educators and Teachers. A fervent champion of enlightenment, Sechenov, already a 74-year-old elder (in the autumn of 1903), appeared as a lecturer at the Prechistenka Courses for workers. By their strict scientific rigor and at the same time popularity, these lectures could serve as a model, and it would seem that such activity by the famous scientist should have evoked only complete respect and sympathy; however, as stated above, dark forces managed to extinguish the beacon of knowledge. Devoting himself entirely to the service of science and the cause of enlightenment, Sechenov carefully avoided administrative activity and participation in the practical life of society, although he was always keenly interested in social issues and events. Just as carefully and invariably, Sechenov avoided any public honors and throughout his entire life did not celebrate a single "jubilee," neither public nor in the tight circle of close individuals. His last will was not to place wreaths or flowers on his coffin and not to make speeches at the grave. His will was respected.

The historian of "the awakening of natural science in Russia in the third quarter of the 19th century," the late Professor Kliment Timiryazev, gives the following brilliant characterization of Sechenov's significance: "If chemistry arose among us through the labors of a whole constellation of talented chemists, if descriptive biology can trace the first impulse toward development in the modern direction back to Tsenkovsky, then physiology must acknowledge its indisputable father in the highly talented and equally original and luminous personality of Ivan Sechenov. It can be said that this was the most typical central figure of the movement that characterizes the epoch we are examining. Scarcely any of the physiologists contemporary to him (with the exception, as always, of Helmholtz, who does not count) possessed such a broad grasp in the sphere of his own research, starting from purely physical investigations in the field of gas dissolution and ending with investigations in the field of neurophysiology and strictly scientific psychology, where he appeared as just as rigorous a thinker as in the field of physiology, provoking strong displeasure among psychologists of the old metaphysical cast. If one adds to this the brilliant, remarkably simple, clear form in which he clothed his thoughts, it becomes understandable what wide influence he exerted on Russian science, on Russian thought, even far beyond the bounds of his audience and his specialty. Those who happened to attend his famous public lecture at which he expounded his Reflexes of the Brain for the first time certainly remember that this lecture was an event not for the Medical Academy alone, but stirred the minds of Russian naturalists far beyond its walls. And of course, future history will acknowledge that not a single Russian scientist had such a broad and salutary influence on Russian science and the development of the scientific spirit in our society, not excluding even his friend Mendeleev, whose scientific merits Ivan Mikhailovich always spoke of with such sincere, unfeigned admiration." Sechenov's collected works were published in 2 volumes (Moscow, 1907–1903 [sic]), edited by Mikhail Menzbier, Lev Morokhovets, and Mikhail Shatershnikov. Sechenov's name was given to the Sevastopol Institute of Physical Therapy Methods and the Physiological Journal of the USSR.