Shoichi Sakata, July 1969
Source: Supplement of the Progress of Theoretical Physics, No. 50, 1971;
First published: as a speech for FM broadcast of NHK on July 30, 1969, published in March 1971 issue of Kagaku (Science), after Sakata’s death.
Transcribed: for the Marxists Internet Archive by Andy Blunden
Physics of atomic nuclei and elementary particles, which is my speciality, is entirely a new field of physics started more or less at the time when I was an undergraduate university student. Since one of our greatest concerns has been how to overcome the old, it may seem that we do not have much to do with the classics. But, creating new things through overcoming the old is the central problem in the method of science or methodology. In this sense, the classics are very important for us. As one of my classics, I want to quote Engels’ Dialektik der Natur (Dialectics of Nature), which has been continuously sending invaluable light into my studies of about forty years as a precious stone. Today, I would like to talk about how I encountered Dialectics of Nature and what influences it gave to my studies in physics.
Let me start with a brief introduction of Engels’ Dialectics of Nature. As you know, Engels was one of the most intimate friends of Marx and he himself is one of the greatest thinkers and philosophers of the nineteenth century. He constructed with Marx, dialectic materialism, the foundation of the so-called Marxism philosophy. He gave indispensable help to Marx for completion of Das Kapital (Capital), which is a new science to elevate the dialectic materialism as a methodology, and, from the early days, he was meditating over the application of the same methodology to the natural science, researches on nature. At that time, there had been made in fields of the natural science a series of new achievements, for example, discovery of the atom and molecule, discovery of cells in a living thing, establishment of the law of energy conservation and Darwin’s proposal of the theory of evolution. All of these achievements were causing bewilderment on the old picture of nature, the so-called metaphysical view on nature, but nobody had ever attained a new and comprehensive picture of nature correctly covering those discoveries. I may say that it was Engels who gave a light to the natural scientists, who had fallen into confusion before those new discoveries. A book published today under the title of Engels, Dialectics of Nature, is a collection of his manuscripts found after his death. A major part of the manuscripts was believed to be written by himself during a period between the early 1870s and 1880s, (1873-1882). In 1878, he published his famous book, Anti-Dühring, in which he described some fundamental problems of the natural dialectic. In 1882, he wrote a letter to Marx, saying that he was expecting to publish his natural dialectic in a short time. Because of a sudden change of the situation, the publication was postponed and never realised while he was alive. What I mean by a sudden change of the situation is the death of Marx in the next year, 1883. After Marx’s death, Engels had to put all of his efforts into the completion of Marx’s Capital. His life itself was finished in 1895, the next year after publication of the third volume of Capital. In this way, the manuscript of Engels’s Dialectics of Nature had to be left unpublished after his death. What made the case more unfortunate was that the manuscript was left in the hands of Bernstein of the German Social-Democratic Party, who had no ability for appreciating the value of the natural dialectic. Therefore, more than thirty years had to pass while the manuscript was relatively unknown and left unpublished. The publication was finally realised in 1925, when Lyasanov of the Soviet Union obtained a photo-copy of the manuscript and compiled German and Russian editions of the book.
Natural science accomplished a still larger revolution after the death of Engels, and its whole system was shaken from the fundamental basis by the so-called three big discoveries at the end of the last century – X-rays (1895), natural radio-activity (1896) and the electron (1897). Reading, for example, the chapter “Crisis of the Mathematical Physics” in Poincaré’s book, La valour de la science in 1905, you will be able to find out what serious surprises those discoveries incited among those natural scientists who did not possess a new view of nature and a correct methodology. The physicists had to lose their credit on the classical theory including Newton’s mechanics and the chemists began to doubt the persistency of elements and indivisibility of atoms. Many of them had fallen into the empiricism and the positivism, seeing that nothing could be more credible than experiences themselves. Mach and Ostwald were the representatives. On the other side, there were people, such as Boltzmann and Planck, who wanted to persist in the old view of nature, and violent disputes developed between the two groups. But, neither of the points of view were enough to seize the essence of the crisis of natural sciences at that time. The man who gave a correct analysis to the problem was Lenin with his view of the materialistic dialectic. His book entitled Materialism and Empirio-Criticism, published in 1908, is being held higher and higher in esteem today, as one of classics of the methodology of contemporary sciences, together with Engels’ Dialectics of Nature.
Analysis of Lenin on contemporary sciences in his Materialism and Empirio-Criticism is, in many respects, in perfect agreement with that of Engels. Since both analyses were made from the same point of view of the materialistic dialectic, it may be no wonder that they were in agreement. But it is remarkable that Lenin did not know at all of the existence of the manuscripts of Engels. As I mentioned before, his manuscript had been buried for thirty years in the hands of a revisionist, who has no estimation of the value of the work, and the publication was made only after the death of Lenin.
Let me now talk about how I happened to encounter Engels’ Dialectics of Nature. I entered Kyoto University for the study of physics after finishing seven-year-studies at Koh-nan High School. I was attracted to theoretical physics since my high school days, reading books by J. Ishiwara, A. Kuwaki, H. Tanabe and others. These authors described serious conflicts among the theoretical physicists who were in confusion caused by the innovation of the relativity theory and of quantum mechanics. Among all, detailed introduction was given of controversies on such problems as methodology of sciences or a world picture, in particular, for the famous dispute between Mach and Planck. I was completely ignorant about Marxism in those days, but I happened to meet in the Esperantist Club, Tadashi Kato, who later became a translator of Dialectics of Nature. I became an intimate friend of his, for he himself was intending to become a theoretical physicist and his house was close to mine. He was very brilliant, and he was behaving like a competent scholar, though he was a high school student. In particular, he was a linguistic genius and mastered a number of foreign languages. Afterwards, he gave up the study of theoretical physics and entered the Faculty of Philosophy and Literature of Kyoto University. It was about this time when he started to translate Engels’ Dialectics of Nature into Japanese. I happened to encounter the natural dialectic for the first time when he came back home on vacation and told me about the book of Engels. As I mentioned to you before, Engels’ Dialectics of Nature was first published in 1925 in the Soviet Union. The Japanese people were able to have access to the natural dialectic relatively early, because the Japanese translation was published as early as 1929, only four years after the original publication. You may compare the situation with that in England, where Engels himself lived for a long time. The English translation was published as late as in 1940. The reason why the translation was published so early in Japan was that Marxism became familiar in Japan and publication was being made successively on translation of the works of Marx, Engels, Lenin and others. But at the same time, we are deeply indebted to the genius of Kato, who mastered both fields of natural and social sciences and in addition was an excellent linguist. The translation of Dialectics of Nature was completed and published as one of the “Iwanami Library” under the joint translation of Kato and Yu-jiro Kako, his friend, though the larger part was made through the effort of Kato himself. The co-translator Kako, was his classmate in high school, and later became an assistant professor of the Faculty of Law of Kyoto University. He resigned his professorship together with Takikawa and other fellow professors at the moment of the famous Kyoto University incident, caused by the militarists, and died not long after while he was still young. Publication of the translation was made in the year I finished high school. I did not find any difficulties in understanding the natural dialectic, because I had already learnt the content directly from Kato in my high school days.
Later, I entered the Department of Physics of Kyoto University and started my studies on theoretical physics. As I began to understand the two revolutionary theories of the present century, the relativity theory and the quantum mechanics, I was gradually becoming aware of the importance of the dialectic view of nature, or the point of view of the natural dialectic. Above all, reading Lenin’s book of Materialism and Empirio-Criticism convinced me of the fruitlessness of the arguments between Mach and Planck at the beginning of the present century. I felt a strong stimulus deep in my heart, to accomplish a practical application in my real research of the natural dialectic as the methodology of contemporary sciences.
In 1932, I became a third year student and started to research in my speciality. The year of 1932 was an epoch-making period in modern physics for a series of revolutionary discoveries. Above all, the discovery of the neutron by Chadwick of England was of the greatest significance for the future direction of the development of physics. I may say that a new field of physics on atomic nuclei and elementary particles was started at this moment.
Before the discovery of the neutron, matter in general was regarded as being composed of protons and electrons only. At the beginning of the nineteenth century, Dolton showed that matter is made from atoms, and we knew by the three great discoveries made at the end of the last century, that the atom is not the ultimate constituent of matter but has a complicated inner structure in itself. The structure of an atom has been made clearer and clearer in the present century. It was discovered in 1911 that an atom is composed of a nucleus and surrounding electrons. Motion of an electron inside an atom was found similar to the planetary motion in the solar system, but Newtonian mechanics could not be applied to the electron motion. Until the nineteenth century, Newtonian mechanics had been esteemed as an ideal of exact sciences and regarded as one of the ultimate rules or the absolute truths, which governs motion of all existences in nature including motion of heavenly bodies as well as atomic motions. But, the mechanics was losing its almightiness, being not applicable to the world of an electron, or the microscopic phenomena. This fact caused a strong reaction to all of the physicists, as did the three great discoveries at the end of the last century. But, a new mechanics was successfully constructed in 1925 which governs the microscopic world. It is discovery of quantum mechanics. Through establishment of the quantum mechanics, atomic physics made remarkable progress in a short time interval. In this way, we were able to understand the microscopic world as well as the macroscopic world.
Before 1932, people still could not enter into the world of atomic nuclei, a still finer world than that of an atom. Many of the physicists were expecting that the quantum mechanics could be applied to nuclear problems, under the assumption that an atomic nucleus is composed of protons and electrons. But the attempts were encountered with various contradictions, reasons of which were hardly understood. Then, Niels Bohr, a discoverer of quantum mechanics, proposed the idea that a new mechanics must be founded which governs the world of atomic nuclei in place of the quantum mechanics. But, he could not find any more fish under the same weeping willow.
Problems of atomic nuclei found the direction for their solution by the discovery of the neutron in 1932. Really, the atomic nucleus is a composite system of protons and neutrons. The reason that kept us away from the understanding was that an unknown kind of particle – the neutron – was playing an essential role in the nucleus. Since then, a rapid progress was made in nuclear physics on the basis of the proton-neutron model of a nucleus.
We must notice here the methodological characteristics which can be found typically in the “establishment of the quantum mechanics” and “development of nuclear physics”. I felt the necessity of analysing those problems from a point of view of the natural dialectics. I tried the analysis in my thesis for my bachelor’s degree, though it was not complete from the present point of view.
After graduation, I became an assistant to Yukawa at Osaka University. Yukawa was writing his famous paper on the meson theory. The meson theory was born from an investigation on the origin of the so-called nuclear force, a force putting protons and neutrons together into a nucleus. He made an assumption that a proton and a neutron are exchanging an unknown kind of elementary particle to be called the meson.
But, the society of physics at that time was deeply influenced by positivistic thought starting from Mach, and people were not willing to accept the Yukawa theory, which introduced an unknown elementary particle. At that moment Mituo Taketani developed a new methodology known as the three-stage theory, and it gave invaluable encouragement to the Yukawa theory. Taketani was my junior by one year in Kyoto University, but I had no chance to talk with him in my student days. When I was working in Nishina’s laboratory of the Institute of Physical and Chemical Research just after my graduation, he sometimes visited the laboratory and we became friendly with each other. After I started my studies with Yukawa at Osaka University, he frequently visited us there and we three began to collaborate on the study. He had profound knowledge in philosophy, science and art, and in addition he had very original opinions. So we enjoyed very much his visit to our laboratory. In those days he was a research assistant in Kyoto University, and he had a close circle of progressive young scholars, such as Shoichi Nakai, Takeshi Shimmura of the Faculty of Philosophy and Literature of Kyoto University and others. Their circle was publishing a journal with the title Sekai-Butika (World Culture). In 1936 he presented in this journal a paper entitled “Dialectics of Nature- on Quantum Mechanics”. It is an epoch-making contribution of a penetrating analysis on the quantum mechanics with a stereoscopic view of the materialistic dialectics. There, he was making a sharp criticism against the one-sided views of the Copenhagen interpretation of Bohr and others which contains strong positivistic tendencies. Through this work he attained “the three-stage theory” which should be placed at the highest level of the natural dialectics. His new methodology has been playing an important role like a compass in our collaborative study since then.
According to Taketani’s three-stage theory, a process of cognition of nature is to be carried out through the three stages: phenomenological — substantialistic — essentialistic stages.
The phenomenological stage is the one in which one observes and describes natural phenomena as they are. In the substantialistic stage, one investigates the structure of the object. Finally, one finds physical rules governing the object in the essentialistic stage. He demonstrated that both of quantum mechanics and Newtonian mechanics were constructed through the above three stages. The positivists are often neglecting the importance of the second stage, while Taketani was defining the situation of nuclear physics at that time as a stage of searching for, a road towards the third stage, through analyses of the second stage. The importance of the discovery of the neutron and also of the introduction of the meson can be understood from his point of view.
Experimental discovery of the meson in cosmic radiation was proving the validity of the Yukawa theory, and at the same time it was showing the power of Taketani’s methodology. Progress of our theory of elementary particles achieved in Japan since then and afterward is deeply indebted to Taketani’s methodology.
Concerning my studies, I made in 1942 the two-meson theory as a development of the Yukawa theory, proposed in 1946 the theory of mixed fields which opened a new way towards Tomonaga’s renormalisation theory, and constructed in 1956 the composite model of elementary particles. All of them were accomplished with Taketani’s methodology of the natural dialectics.
Engels is telling us in his Dialectics of Nature that nature is composed of various strata of different properties, on each of which the respective proper physical laws are operating. Those strata are neither isolated nor independent with each other, but are mutually dependent and correlating among themselves. They are in the midst of generation, annihilation and also mutual transformation, and are constituting nature as the whole unified existence. The three-stage theory of Taketani is developing a methodology for cognition of the individual strata on the basis of such a view of nature. Correctness of the dialectic view of nature has been made clearer and clearer by rapid progress of science after the death of Engels. On the old and fossilised metaphysical view of nature before Engels, one believes that nature is ultimately composed of atoms, which are eternal and indivisible, and their motion is governed by Newtonian mechanics, which is a final law over the whole existence. But, such an old point of view had to be abandoned as science made remarkable progress. Still, there remain even today a number of. physicists who believe the elementary particles to be the ultimate constituents in place of the atoms of old days, and wish to make a revival of the metaphysical picture of nature. There are, too, many of those with the positivistic point of view, who regard the concept of elementary particles as nothing but the so-called useful working hypothesis of Mach. It may be concluded that all of those people are remaining blind to the development of sciences after Engels, and do nothing but try to prevent a new step of cognition of nature beyond the stratum of elementary particles.
I used to keep on my desk a note with the following sentences of Engels. It says, “Essence of the modern atomism lies not only in its claim of discontinuity of matter, but also in its emphasis that those elements of the discontinuity, atoms-molecules-bodies-heavenly bodies and others, are the nodal points which restrict various qualitative mode of existence of matter in general.” In addition, I can never forget a famous phrase of Lenin in his Materialism and Empirio-Criticism, which says that even an electron is as inexhaustible as an atom is. Those are indeed encouraging me to confront the view of regarding elementary particles as the ultimate of matter and to concentrate on the study of the composite model, with a standpoint of the stratum of matter.
At the end, I would like to refer to the doctor thesis of Marx in its relation to Dialectics of Nature Dialectics. His thesis was entitled “On the difference between the atomism of Democritus and that of Epicurus.” I think that he is pointing out a difference of great significance. The atom of Democritus is a perfect existence created by God, so that it may be regarded as the intimate of matter. But, the atom of Epicurus is imperfect, because it contains accidental elements, which may be regarded as a stratum of matter. I think that the thesis should be highly appreciated, because it destroyed the current view that Epicurus was an Epigone of Democritus and it placed a proper estimation on Epicurus for opening a new road towards the dialectic view of nature.