Galen on Apodictics

On the other hand, the judgment of early Ionian physics (6th century BC), as the starting point of nature research nucleation from a rational methodology, also became general in modern historiography. In this case, the rationalism of ancient science means the union of astronomical, biological, etc. phenomena by not mystical, but natural physical causes. The three natural sciences specialties—mathematics, astronomy and medicine—are considered to be the most ancient; its appearance is directly related to the early Ionian physics. As early as the beginning of the 4th century BC we see the existence of an absolutely clear system of mathematical knowledge, an astronomical theory based on practical observations, and medicine of Hippocrates. It is in the context of the analysis of its history in the special literature that the discussion of the problem of the apodictic method of knowledge begins. In the 1960s, G. Lloyd6 for the first time very pointedly and reasonably raised the question of the separation of mystical and occult chiliastic practices from the development of ancient Greek rational medicine. And here it becomes clear that it is precisely the development of medicine that historians and philosophers can judge most reliably in view of the quality of the source base: nothing like Hippocratic Corpus is at the disposal of scientists studying the birth of other disciplines. Thus, it turned out that the historically accurate picture of the history of medicine has the best background. Further, G. Lloyd raised the question of the apodictic method of knowledge in the rational medicine of antiquity. It also dealt with the absolute opposition of a clear, structured logical proof to sophistic tricks. Ideally, the apodictic method in medicine should, according to the degree of evidence of the proof, approach the mathematical method. In this sense, the application of the “apodictic” concept to medicine can be regarded as a rather free extrapolation of the concept from the mathematical science vocabulary. However, the Hippocratic Corpus has already shown obvious evidence, with which to argue is as difficult as with a mathematical formula—an anatomical autopsy has become such. G. Lloyd, in fact, was the first who absolutely clearly defined the dissection as a medical apodictic. In addition, a significant number of arguments by G. Lloyd, based on a thorough analysis of sources, relate to the principles of analysis and reflection on clinical experience.

J. Longrigg asserted the incomprehensible differences, comparing medical schools of antiquity. He linked only very definite theories with later history of medicine. In the last decades of 20th century the concept of “ancient Greek rational medicine”, which denoted precisely this direction, was firmly established in historiography.

It means a clear separation of Alkmeon and Hippocrates medicine, which is based on a completely clear natural-philosophical theory, from temple healing, ritual incubation, invoking spirits and other non-rational chiliastic practices. Apodictic (in the understanding of G. Lloyd) cautiously and not quite consistently begins to recognize the basis of the methodology of rational medicine of antiquity. The reason for this caution, I think, is the difficulty with a clear classification of practical knowledge. However, after J. Jouanna was able to describe the basic principles of the clinical practice of Hippocrates7 these difficulties can be considered overcome. I suggest to use the term “clinical systematics”: this is how we can describe the principle of understanding the whole set of practical knowledge about diseases and its treatment, specific to the Hippocratic school. Its development is underway, Galen only emphasizes the hierarchical, logically built and striving to match the particular and the general (that is, “systematic”) nature of the comprehension of practical experience.

The works of V. Nutton have an outstanding meaning in the development of the study of the history and methods of ancient medicine. Due to decades of hard work of V. Nutton, his co-authors, students and followers, the problem of historically reliable reconstruction of the main events of almost a thousand-year-old history of ancient medicine was, in general, solved.8

The availability of sources that allow making an impression about the development of ancient medicine after Hippocrates leaves much to be desired. It is with this that I associate the fact that in modern scholarly literature there is a tendency to consider hippocratics-rationalists and, for example, doctors-empiricist, equivalent historical phenomena. The connection between clinical practice and philosophical theory in the teachings of various medical schools is often misunderstood, their mutual exclusivity is sometimes underestimated. The main sources containing information about antiquity medicine from the 3rd century BC and later, are the works of Galen: 111 out of more than 500 reached us. However, fewer than half were translated into English, fewer than 30 texts into Russian.

Speaking of underlying methodological problems arising when studying the medical texts of Galen, above all, the conceptual framework of the 2nd century doctor has to be compared with the professional “world view” of the modern-day doctor. This pertains to the problem T. Kuhn9 called the “incommensurability” of scientific knowledge, identifying it as key when working on translations and interpretation of sources. The question of “incommensurability” of theoretical conceptions arising in different epochs caught the attention of leading scientists in the last quarter of the 20th century.10 In my opinion, the question of the effect of change of scientific theory on the meaning of special terms bears particular significance. When Galen spoke of “inflammation”, did he mean that which modern pathophysiologists and doctors understand as inflammation? What is the relationship (if at all) between “cancer” in a patient observed by Galen and “cancer” as understood by an oncologist in the 21st century? The fact that the overwhelming majority of terms used by Galen remain in the vocabulary of the modern doctor stands out. However, in what sense were they used in the 2nd century and what do they mean today? In this case comparability of meanings indicates the ontological commonality of our thinking and the world view of the rationalist doctor, which belongs to the Hippocratic tradition. Considering the importance of this issue and its crudity in local academic literature, I think serious attention should be paid to the assessment of the problem of the “incommensurability” of the theory by T. Kuhn himself.

T. Kuhn notes that the concept of “incommensurability” in respect to the theory of science should be interpreted metaphorically. This means that “no common measure” should mean “no common language”, which essentially does not entail incomparability as well. Most of the terms and concepts can be interpreted in the same manner in “old” and “new” theories, i.e., their original meaning is retained. It is only for a very small group of terms that the problem of translation arises, and all of this, to my point of view, can be considered “partial commensurability”.

We will try to illustrate the foregoing with a specific example—the term “apoplexy” used by Galen. In literature, this concept is often associated with the modern-day nosological entity of “stroke”. Such an interpretation has the right to exist, it is certainly logical from a clinical point of view.11 However, broadly speaking, Galen’s “apoplexy” should not be considered exactly the same as the modern term “stroke”.12

What did Galen mean by the term “a fit of apoplexy”? In one of his works, he defined apoplexy as a state when there is simultaneous loss of sensation and motor functions. The definitions and descriptions of this disease may differ in his various works, but this difference can be reduced to a common denominator. Apoplexy is characterised by the following symptoms: abrupt manifestation of disease, comatose state, violation of motor functions of the entire body, simultaneous loss of sensation, shallow breath, weak, slow pulse, violation of speech function, chronic disease progression. This often has a fatal outcome. The addition of fever to the above-described symptoms may have led to the condition Galen referred to as “lethargos”, i.e., loss of mobility and sensation of a certain side of the body. The concept which corresponds to its description in today’s medical vocabulary is “paralysis”. On the other hand, Galen’s understanding of the term “apoplexia” (“fit of apoplexy”) was broader than today’s. The modern-day doctor may associate a case of sudden, simultaneous, complete loss of mobility and sensation, including with impairment of consciousness and breathlessness with the manifestation of several diseases, starting with brain trauma, heart attack or pulmonary embolism with loss of consciousness and ending with acute toxic response. The equation of the meaning of a fit of apoplexy in Galen’s work with the modern-day concept of stroke, which, at first sight, seems obvious, may lead the medical historian to the wrong interpretation of the text of the source.

For ancient doctors, the correct prediction of the course and outcome of a disease was more important than terminological nuances of diagnosis. Hence, depending on the severity of the disease, Galen drew a distinction between two forms of apoplexy, which are judged based on the familiar symptoms of irregular breathing and pulse. Critical deviations from the natural respiratory rhythm and the corresponding changes in pulse pointed to an incurable form of apoplexy with high likelihood of a fatal outcome. Minor violations of vital functions enabled to make an optimistic prognosis of the course of the disease. However, already at the stage of this distinction, the difference between the views of Galen and the views of the modern doctor with pathogenetic thinking is noticeable. Galen considered breathlessness as only the result of the patient’s failure to move chest muscles. In other words, his ideas are also associated with anatomical-physiological factors, but exist in a different “explanatory model” from today’s—investigative capabilities determine the type of rationality of the scientist.

In order to understand Galen’s views, how he explained the origin of the fit of apoplexy is crucial. To this end, a concrete clinical problem in Galen’s system of general pathology—the theories of the movement of blood and the balance of the four humors—has to be examined. According to the Platonic tradition, of which Galen was an advocate, blood is continuously synthesised from assimilated food. Part of the food, which is useful for this purpose, is absorbed from the stomach and carried through the portal vein to the liver. There, it is converted to venous blood and “vegetative spirit” (pneum, generated by lower part of the soul), which supports the functions of growth and nourishment, and spreads to all parts of the body through veins. Inspired air becomes “vital spirit” (pneum, generated by middle part of the soul) upon entering the left half of the heart. The heart and arteries are responsible for maintaining and distributing natural heat (this was one of the key principles of the medical theory of Aristotle, as interpreted by Galen). This concept explained the fundamental principles of the functioning of the body. Galen believed that, while passing through the arteries, both the blood and the “vital pneuma” warmed up parts of the body, nourished them and maintained their vital function. The transformation of “vital spirit” occurred in the arteries, which formed the so-called “rete mirabile”—a network of vessels which, according to Galen, was located at the base of the brain. It is specifically in the rete mirabile that “vital spirit” turned into the “animal spirit” (pneum, generated by higher part of the soul), which Galen believed was located in brain ventricles (the fourth ventricle played the main role in his theory) and was the mediator for the transmission of motor and sensory pulses to all parts of the body. The transmission process occurred through the flow of the “animal spirit” via nerves, which Galen thought of as hollow tubes. The “animal spirit” reached specific body parts, passing them arbitrary “commands” from the higher, “rational” part of the soul located in the brain. This way, Galen attempted to establish the principles of interaction between the blood circulatory system and the nervous system. His model was based on Plato’s tripartite theory of soul, the concept of the three kinds of pneuma13 and the idea that the brain is the centre of control of the arbitrary functions of the body.

Galen’s theory was also based on the Hippocratic theory of the four liquids—blood, phlegm, black bile and yellow bile,—and their associated qualities—hot, cold, moist and dry. Overabundance of one of the humors could be the reason for the violation of their good mixture (or “dyscrasia”), leading to the dysfunction of the body in the form of any given disease. Galen considered two scenarios of the development of apoplexy. In one case, he suggested the possible development of apoplexy in the form of local “dyscrasia”; the accumulation of a dense, viscous and sticky fluid in brain ventricles blocked the movement of the “animal spirit”, which in turn made difficult or stopped the transmission of sensory and motor pulses between the brain and other parts of the body. In the other case, which best matched the modern concept of hemorrhagic stroke, apoplexy developed as a result of local plethora. Brain tissue is overfilled with excess blood, which squeezes it. The result of this excess pressure is the impairment of the functions of the brain as the centre of control of body parts. In this case, Galen does not explicitly claim that the plethora of the brain is the result of haemorrhage. Ultimately, at the last stage, both scenarios of the development of the disease lead to a critical change in the temperature of the brain and subsequent cessation of the circulation of the “animal spirit”.

Galen’s interpretation of the causes of brain injury as the pathological change in the movement of the “animal spirit” enabled to consider disease as a result of anatomical and functional violation of the unity of the spiritual and the corporeal. Furthermore, such a view took into consideration the possible pathogenetic effect of body ageing processes and external factors on the likelihood of the development of apoplexy. During clinical observations, Galen paid attention to the fact that the average body temperature in the elderly was usually lower than in younger people. It followed that their bodies were more susceptible to the so-called cold diseases, for example, caused by excess yellow bile. Also of great significance were climatic and seasonal factors, which influenced the “good mixture” of liquids (for example, sparking an increase in the accumulation of yellow and/or black bile in the body). Overcooling of the brain with subsequent development of bouts of disease could be a result of an unhealthy lifestyle. Any excessive eating was considered harmful: in particular, excessive consumption of wine, according to Galen, reduced natural body heat and was undesirable. The plurality of external factors, such as climate and season, and internal predispositions (age, bad habits, etc) led to the cooling of the body and was the cause of “cold” diseases.

The basic definition of stroke in modern clinical practice is “cerebral circulation disorder”. Of course, the meaning of this nosology changes over time. For instance, in the late 1980s, E.I. Gusev offered the following definition: “Stroke is acute cerebral circulation disorder”.14 Therefore, based on the nature of the pathological process, he divided stroke into ischemic stroke and hemorrhagic stroke. Hemorrhagic strokes are hemorrhages in brain matter and under the brain lining. Mixed forms of stroke were also identified, for example, subarachnoid-parenchymal stroke. Ischemic stroke is basically cerebral infarction as a result of thrombosis or embolism of the extra- or intracranial vessel. The etiological version could be neurothrombotic stroke, which is associated, for example, with atherosclerotic vascular disease. The essence of the matter is the same—violation of blood supply to the brain.15 The interpretation becomes more complicated over time: N. N. Yakhno no longer uses the term “hemorrhagic stroke” in 2007, instead calling this disease “intracerebral hemorrhage”; however, the description of etiology and pathogenesis does not change drastically. “Stroke” now means only what was previously called “ischemic stroke”. This disease certainly belongs to the group of diseases which relate to “acute cerebral circulation disorder”.16 The risk factors for the development of such disorders primarily include arterial hypertension. Furthermore, most authors make reference to old and senile age, hyperlipidemia, hyperglycemia, often associated with insufficient physical activity, obesity and bad habits. It is natural that constant stress and psychoemotional overburden feature among risk factors of stroke itself and among preconditions for the development of its primary cause—arterial hypertension.17 Take note of the fact that the classification of stroke is refined even at the modern-day stage of the development of science: in the twenty years separating the publication of E.I. Gusev’s textbook and the guide edited by N.N. Yakhno, significant amendments18 have been made to this classification.

Now let us compare Galen’s interpretation of apoplexy and the modern definition of stroke—their similarities and differences are clear straight away. It is interesting that T. Kuhn’s general views on partial incommensurability and the interpretation of the text are brilliantly confirmed by this example. The modern-day meaning of the pathogenesis of stroke is based on the concept of cerebral circulation disorder. This factor basically implies overall disturbance of nutrition and vital activity of the affected part of brain matter. Obviously Galen could not explain the function of the blood, the significance of gas exchange in tissue, etc. However, his understanding of apoplexy as the impairment of the mechanism of the circulation of the “animal spirit” touches on the issue of ensuring normal activity of the brain, which, according to Galen, was ensured by the flow of blood and the “animal spirit” in the arteries. Furthermore, apoplexy, which, according to Galen, is caused by excess blood and local plethora, has many similarities with the modern-day concept of intracerebral haemorrhage. Galen calls the dropping of brain temperature as a result of the impairment of the mechanism which ensures its normal activity and “clogging” with breakdown products another factor (besides circulation of pneuma) of the pathogenesis of apoplexy. Holding forth on the risk factors of the development of apoplexy, Galen lays out the preconditions for the formation of the modern view on the problem of stroke—dietary regimen, age and physical exercise. This is largely associated with his methodology, which is based on the doctrine of the unity of the corporeal and the spiritual in the human body, which enables to take into account the impact of the psychoemotional component as a pathogenetic factor.

A crucial attribute of Galen’s medical theory, which could be called “natural philosophy of medicine” has to be emphasised. In it, disease was not associated with anatomical location and a special etiological factor. In other words, in order to understand Galen, we have to ditch the modern conception of disease (or go beyond its bounds). Nonetheless, similar to how T. Kuhn compares the physics of Aristotle, I. Newton and A. Einstein, doctors, while recognising the difference between the medicine of Galen, S.P. Botkin and E.M. Tareev, have to keep in mind the various types of scientific rationality, which are typical of different historical phases of the development of science.

Galen explains the phenomena of medical practice in the language of philosophy. For example, when analysing his treatise On the Doctrines of Hippocrates and Plato19, it should be remembered that in the debate on the “soul”, we are dealing not with the modern language of philosophy and theology, but with the specific language of science of that time, wherein this concept had meanings different from those familiar to us. The same applies to the strictly medical language of the Galenic clinician. This is the very same question of the “commensurability” or “incommensurability” of scientific knowledge from different eras. Galen also explains physiological processes occurring in the human body using the category of “soul”. For instance, digestion and haemopoiesis occur with the direct involvement of the “inferior parts of the soul”, which are located in the liver: for food to be properly absorbed into the body, and for primary elements to properly replenish anatomical structures of various parts of the body, there is need for the active presence of the “vegetative spirit”, a type of endogenouss pneuma, which is a derived from the inferior, “desiring” part of the soul. The liver is particularly the organ which forms blood and saturates the blood with nutrients. The process of digestion and absorption ends in the liver, and functions of venous blood begin from it. The same applies to the other two types of endogenous pneuma which, according to Galen, are derived from the activity of the superior (rational) and middle (violent) parts of the soul. They particularly explain the realisation of the functions of the brain, heart and arterial blood. Therefore, according to Galen, diseases of the soul should be approached from the same standpoint as diseases of the body.20

Discussing the matter of commensurability, I also suggest to use the Stepin’s classification: classical, nonclassical, post-nonclassical paradigms of cognition.

The potential of Galen’s system is defined by the principle of teleology, which is the basis of his views on the human being. In this case, the term “teleology” is used in the classical sense as a “practical function”. It is about the view on the structure of animals and human as being practical in relation to the function they perform. However, this principle has another side. It determines the potential use of the system of investigation (the ability to allow the governing paradigm to take in and absorb new facts). A teleological view of the anatomy of the human being provides a deep conviction of the extreme importance of every detail, both known and unknown. It constantly stimulates the explorer to new observations and research. On the one hand, the human organism is knowable; on the other hand, doctors are never satisfied with the amount of knowledge they have and try to expand it.

This is why Galen focuses on the views expressed by Plato, particularly the concept of the psychosomatic unity of the human. It should be clear to any historian of medicine that without the appropriate evaluation of the soul, the body and their interactions, there could be no integrated approach to the diagnosis of illness and its treatment.

Great danger lurks in wait for the scientist when historical and philosophical inquiry is focused solely on specific details of the professional work itself and sets out to answer only the questions: “who discovered?”, “how did they discover it?” The question why a particular scientist at a certain time and place made their discovery is not even considered. And it is not considered because the medical historian lacks the necessary package of general philosophical and general historical knowledge.

Speaking of the history of any given scientific discovery or the establishment of general theoretical ideas in medicine (or physics, for example), I am certainly trying to understand the “anatomy” of the mind of the inquirer, to find out how any given idea came about, the path of the scientific search by a particular scientist. Of course, these questions cannot be answered without the description of the figure of the inquirer himself. Reconstruction of the biography of the scientist, details about his education, information about his family and social surrounding are always the focus of attention of historians of science. Simply put, I am trying to answer for myself the question: “How did he come up with the idea of his discovery?” Thereafter, the following question immediately arises: “Why specifically him (and not someone else) and why at that place and at that time (and not some other time)?”