S. A. Brandis

On the 90th Anniversary of the Publication of I. M. Sechenov’s Treatise Reflexes of the Brain

Ninety years ago, in the autumn of 1863, the newspaper Medical Herald published Reflexes of the Brain, a work by Ivan Mikhailovich Sechenov, the father of Russian physiology, a champion of a materialist understanding of the foundations of psychology, and the founder of occupational physiology.

During the preparation and promulgation in 1861 of one of the most hypocritical acts of the Russian autocracy—the law on the “emancipation” of the peasants—peasant unrest intensified. These events resonated among the progressive Russian intelligentsia and influenced the subsequent development not only of the political struggle but also of all branches of knowledge, and above all the natural sciences.

I. M. Sechenov’s treatise thus appeared at a time when Russian materialist philosophers, fighting autocracy and reaction, were winning for Russian science a leading role in the struggle against idealism in philosophy and the natural sciences. The philosophical generalizations in the works of A. I. Herzen and in the subsequent writings of the democratic philosophers N. G. Chernyshevsky, D. I. Pisarev, and V. G. Belinsky prepared the ground for substantive interventions by biologists such as I. M. Sechenov, K. A. Timiryazev, and others.

For a number of years I. M. Sechenov had been developing the ideas that formed the basis of Reflexes of the Brain. In his autobiographical notes he wrote: “I returned to St. Petersburg in May 1863 and spent the entire summer writing a work that played a certain part in my life. I mean Reflexes of the Brain.

“My doctoral dissertation of 1860 contains the following two propositions: ‘All movements that in physiology are called voluntary are, in the strict sense, reflexes’; and ‘the most general characteristic of normal brain activity, insofar as it is expressed in movement, is a lack of correspondence between excitation and the action and movement it produces.’”¹

Sechenov continued: “...these thoughts were also fermenting in my head during my stay in Paris in 1862, but on my return... they had apparently settled in my mind... These propositions formed the outline that served as the basis for the short treatise I wrote under the title An Attempt to Introduce Physiological Foundations into Mental Processes.”² At the censors’ demand, Sechenov subsequently changed the title of the treatise to Reflexes of the Brain. Its final completion followed a series of brilliant experiments that demonstrated for the first time in the history of world physiology the—

¹ I. M. Sechenov, Autobiographical Notes, USSR Academy of Medical Sciences Press, Moscow, 1952, p. 183.
² Ibid., pp. 184–185.

…of inhibitory processes in the central nervous system, in the brain, that suppress spinal reflexes.¹

This “attempt to introduce physiological foundations into mental processes” was a truly scientific and civic achievement on the part of I. M. Sechenov, vividly demonstrating his materialist understanding of life processes, his deterministic approach to the analysis of mental and physiological phenomena, and his profound patriotism and humanism.

Already in the brief introduction to the treatise, I. M. Sechenov wrote that his work was directed against idealism and metaphysics in science and that he supported the progressive ideas of philosophical materialism held by his contemporaries—the revolutionary democrats and materialists A. I. Herzen, N. G. Chernyshevsky, N. A. Dobrolyubov, D. I. Pisarev, and others. In asserting that “…the brain is the organ of the soul,”² I. M. Sechenov declared war on the concepts of psychophysical dualism and psychophysical parallelism, as well as on the other fictions of idealists and metaphysicians of every kind. Sechenov’s conception accords with the fundamental tenets of philosophical materialism concerning the materiality of the world, the primacy of matter and the secondary nature of consciousness, and the brain as the organ of thought. All the subsequent propositions of Sechenov’s treatise confirm and develop this fundamental principle in every respect.

If the first chapter, “On Involuntary Movements,” can be regarded as strategic preparation for a full-scale offensive against the old idealist psychology, the second chapter, “On Voluntary Movements,” is truly the scene of a great battle to establish a materialist basis for all the principal concepts and phenomena treated by human psychology. The following statements by I. M. Sechenov offer vivid proof of this: “…thought is considered the ordinary cause of an action. If, however, the external influence—that is, sensory stimulation—goes unnoticed, as happens exceedingly often, then, of course, thought is even taken to be the initial cause of the action. Add to this the very pronounced character of subjectivity in thought, and you will understand how firmly a person must believe the voice of self-consciousness when it tells him such things. And yet this is a monstrous falsehood. The initial cause of every action always lies in external sensory stimulation, for without it no thought is possible”³ (italics by I. M. Sechenov).

Running through both chapters of the treatise is the central idea that a person’s entire mental life is closely bound up with the surrounding environment, which stimulates, sustains, and directs it. This connection is established through those sensory elements of the central nervous system that perceive the stimuli constantly impinging on the body’s receptor fields. “The first cause of every human action lies outside the person” (italics by I. M. Sechenov).⁴ This brief, striking thought brings into focus Sechenov’s entire fundamental conception of the significance of the interaction between environment and organism for higher nervous activity and for human mental life.

Alongside these principal general propositions, which constitute the essence of the work on brain reflexes, it is necessary to touch briefly on a number of specific propositions advanced in I. M. Sechenov’s treatise…

¹ I. M. Sechenov, On the Mechanisms in the Frog’s Brain That Inhibit Spinal Reflexes, Berlin, 1863.
² Ibid., Selected Works, USSR Academy of Sciences Publishing House, Moscow, 1952, p. 8.
³ Ibid., p. 104.
⁴ Ibid., p. 123.

… and of the utmost importance to hygienists and occupational physiologists.

Analyzing the emergence of involuntary movements in response to unexpected influences from the external environment, and assessing the importance of their strength and unexpectedness, I. M. Sechenov not only vividly depicts the mechanism of central inhibition that he discovered, but also makes a first approach to explaining the mechanism of habituation to various stimuli impinging on receptive fields from the external and internal environments, and to interpreting and, most importantly, realistically assessing the mechanisms of adaptation: “...everyone knows,” writes I. M. Sechenov, “that the process of becoming accustomed to many things costs long and terrible efforts.”¹ These are his first indications of the ways in which the organism adapts to various environmental conditions, of the paths of training, and also of the “cost” to the organism, if one may put it so, of this process of adaptation. These thoughts are akin to I. P. Pavlov’s ideas on the dynamic stereotype, later discovered by the great successor to Sechenov’s nervous physiology. I. M. Sechenov’s observations and his understanding of the phenomena of adaptation and training are undoubtedly of great importance and interest both to the hygienist studying the relationship between the organism and its environment and to the occupational physiologist who has devoted his research to modifying the rational organization of the work process in the performance of various industrial operations or work movements.

I. M. Sechenov then turns to another question of the greatest importance to the hygienist: the significance of the state of the nervous system for the perception of and response to various influences from a person’s surroundings, and the paramount importance of emotions and of the general tone of the organism’s autonomic-endocrine apparatus. I. M. Sechenov’s words that “...the character of a sensation changes with a change in the physiological state of the nerve center”² could hardly reflect the foregoing more aptly and are, in essence, nothing less than an anticipation of the brilliant experiments conducted by A. A. Ukhtomsky and his colleagues, which enabled him to formulate the doctrine of the dominant focus.

The treatise also examines in detail one of the “obscure” senses—the muscular sense. I. M. Sechenov interprets it, in a manner consonant with our own time, as a multitude of proprioceptive stimuli traveling from the organs of movement to the cerebral cortex. These are the signals from the organism’s internal environment that Academician K. M. Bykov studied in such detail and analyzed using the methods of Pavlovian experimentation, and that are of such great importance to the researcher concerned with hygiene and occupational physiology and with fatigue.

The great physiologist’s treatise opens up broad horizons in questions of human upbringing, beginning in early childhood, and the shaping of conscious life. Not only the psychologist and educator, but also the hygienist and physiologist can find a wealth of valuable observations and statements here. Consider, for example, this proposition of I. M. Sechenov: “...in general, if a person or another animal is frequently subjected in life to powerful external influences acting on its senses, then that person or animal has a good chance of greatly developing the ability to resist them.”³

The treatise contains many ideas and observations that found expression and experimental development in the laboratory of Academician I. P. Pavlov, in his doctrine of higher nervous activity and in

¹ I. M. Sechenov, Selected Works, Publishing House of the Academy of Sciences of the USSR, Moscow, 1952, p. 19.
² Ibid., p. 31.
³ Ibid., p. 100.

especially in the part of this doctrine concerned with the relationship between the first and second signal systems in the activity of the human brain.

Academician I. P. Pavlov regarded I. M. Sechenov’s Reflexes of the Brain as a brilliant leap of Russian scientific thought and believed that, for scientific Russia, the memory of I. M. Sechenov must remain forever dear.

For us—hygienists and occupational physiologists—the 90th anniversary of the publication of I. M. Sechenov’s brilliant work is also important because it draws our attention to a number of other scientific works by the great physiologist in which the propositions of the treatise are developed. Only a few can be mentioned here: Physiology of the Nervous System (1866), On the Elements of Visual Thought (1877), Elements of Thought (1878), Physiology of the Nerve Centers (1891), Physiological Criteria for Determining the Length of the Working Day (1894), The Participation of the Sense Organs in Manual Work in the Sighted and the Blind (1901), An Outline of Human Work Movements (1902), The Participation of the Nervous System in Human Work Movements (1902), and On the Question of the Influence of Sensory Stimulation on Human Muscular Work (1904).

All the principal propositions of I. M. Sechenov’s treatise formed the foundation of I. P. Pavlov’s subsequent investigations. What had been a brilliant anticipation on I. M. Sechenov’s part was experimentally confirmed and extensively developed by I. P. Pavlov. Pavlov discovered, analyzed, and applied in practice, toward the constructive solution of many problems of physiology and medicine, a most universal physiological phenomenon—the temporary connection, or conditioned reflex.

It is therefore entirely natural that the modern application of Sechenov’s propositions in hygiene and occupational physiology, in education and physical training, can be methodologically sound and practically fruitful only on the basis of I. P. Pavlov’s doctrine of the temporary connection between the organism and its environment, which in human beings is realized through the functional interrelationships of the first and second signal systems.