Ibn Sina. The Canon of Medicine
The first book presents theoretical medicine. It serves as a unique textbook on anatomy and physiology with a preface to internal diseases.
The book is divided into four parts.
The first part provides a definition of medicine, the second discusses diseases, the third focuses on health preservation, and the fourth addresses treatment methods.
The second book describes simple medicinal substances, outlining Ibn Sina’s teachings on medicines, their nature, and their testing. It details 785 simple plant, animal, and mineral medicinal substances, indicating their effects, methods of application, and rules for collection and storage. Of the 396 plants mentioned in the “Canon,” 165 are used in modern medicine.
The book consists of 2 parts.
The first part discusses the general properties of medicinal substances. The second examines medicinal forms and lists their effects on the body and treatment of diseases of specific organs. In other words, the second large part of the book is dedicated to describing the properties, methods of preparation, application, and effects of individual medicinal agents. The second book was, in fact, the most comprehensive textbook on pharmacology of its time.
The third book, the most extensive, is dedicated to pathology and therapy – the description of individual diseases and their treatment.
It consists of 22 parts, dedicated to specific organs and systems.
Each part provides descriptions of the anatomy and physiology of the corresponding organ and system. Then, the pathology of that organ is discussed, along with the causes and symptoms of diseases. After that, the methods of treating the corresponding disease are outlined. This book can be considered a complete textbook on specific pathology and therapy.
The fourth book consists of 7 parts and is dedicated to surgery, the treatment of dislocations and fractures, and general teachings on fever (crises in diseases). It discusses tumors, purulent inflammations of subcutaneous tissue, as well as infectious diseases. It addresses the main issues of the doctrine of poisons.
The fifth book contains a description of “compound” medicines, as well as poisons and antidotes. The fifth book is essentially a comprehensive pharmacopoeia for its time. It details the preparation of compound medicines and their application.
The book consists of two chapters. The first describes medicinal forms, their preparation and storage, while the second outlines the methods of applying medicinal substances for various diseases. At the end of the book, units of measure and weights are provided.
Ibn Sina associates the causes of diseases in “The Canon of Medicine” with endogenous and exogenous factors. He clearly understands the relationship between inhaled air and the spread of infectious diseases. According to him, “smallpox and measles are among the contagious diseases and increase after southern winds, when they blow frequently.”
Thus, more than eight centuries before the discovery of Antonie van Leeuwenhoek – the creator of the first microscope and the first to discover the invisible to the naked eye “animalcules,” i.e., microorganisms – Ibn Sina expressed the idea of the possibility of hidden causes of diseases.
In “The Canon…” there is a sufficiently detailed description of the clinical picture of meningitis, pleuritis, pneumonia, peritonitis, gout, peptic ulcer, malaria, cholera, smallpox, measles, rabies, schizophrenia, kidney stones, and gallstones, helminthiases, various fevers, treatment of wounds and abscesses, skin and hair care, and much more. The descriptions of the physical properties and macroscopic characteristics of sputum, saliva, sweat, urine, and feces provided by Ibn Sina can be considered, in essence, the first and unique laboratory studies.
He also pays attention to physical exercises, both heavy and light, recommending not to limit oneself to one type of sport, but to engage in several and different ones, according to the state of a person’s physical health.
In “The Canon of Medicine,” Ibn Sina identified 6 degrees of health and disease (modern scientists, for example, academician Amosov, introduced the concept of “quantity of health”).
Very often on the pages of “The Canon…” (almost every three pages) there are mentions of “medicinal food” and “food medicines.” This is evidently related to the fact that in traditional medicine of Southeast Asia, there are very few toxic medicines, and among them, many plants are used as food.
From Chinese medicine, Ibn Sina borrowed the concept of “quality” of food or medicine (in Chinese medicine, they are called “four properties” or “four Qi”). They are taken into account when treating diseases and are determined based on sensations in the mouth and sensations in the body.
Thus, each medicine and each food has its quality. There are 4 – hot, cold, dry, and moist. The expressiveness of quality characterizes the nature. It has 4 degrees.
In addition, the quality of each medicine and food is divided into three parts: at the beginning, middle, and end. For example, at the beginning, middle, or end of the II degree.
Thus, in fever, internal heat, “cold” products are eaten; in chills – “hot” ones; in increased sweating, salivation, diarrhea – “dry” (astringent); in dry cough, dryness in the mouth, constipation – “moist.” This can assist in eliminating disease and maintaining health.
Degrees of the nature of medicines:
If the consumption of a small amount of medicine manifests its quality in the body and the consumption of a large amount, its repeated use leads to insignificant changes, this is the I degree of quality.
If the consumption of a small amount of medicine leads to the emergence of a predominant quality and its further consumption does not harm the body, does not spoil the nature, this is considered a medicine with quality II degree.
If the medicine, upon entering the body, leads to changes at the border of normality, destruction, harm, not lethal to the body, it is considered III degree of quality.
If the medicine upon consumption leads to harm to the spirit, to mortal danger, this is considered IV degree of quality, regardless of whether it is hot, cold, dry, or moist quality.
The nature of compound medicines is determined by the following formula:
I degree = 2 parts of expressed (v.) quality + 1 part of the opposite (p.) quality. Accordingly:
II degree = 3 v. + 1 p.
III degree = 4 v. + 1 p.
IV degree = 5 v. + 1 p.
For example, if the medicine is hot in the III degree, then its formula = 4 parts of heat + 1 part of coldness.
Example: The collection consists of 3 parts of hot in the I degree herb and 1 part of cold in the III degree herb. The nature of the collection = 3 (2 hot + 1 cold) + 1 (4 cold + 1 hot) = 7 hot + 5 cold, which corresponds approximately to the I degree of heat. The same procedure is carried out concerning dryness and moisture. The weight part is taken as the optimal dose of the preparation.
Second example:
The collection consists of 1 part of St. John’s wort, 2 parts of lemon balm, 2 parts of knotweed.
St. John’s wort – hot and dry in the III degree. 4 hot + 1 cold + 4 dry + 1 moist.
Lemon balm – hot in the II degree and dry in the I. 3 hot + 1 cold + 2 dry + 1 moist.
Knotweed – cold in the I degree and dry in the II. 2 cold + 1 hot + 3 dry + 1 moist.
Calculation formula:
4 hot + 1 cold + 2 (3 hot + 1 cold) + 2 (2 cold + 1 hot) + 4 dry + 1 moist + 2 (2 dry + 1 moist) + 2 (3 dry + 1 moist) = 14 hot + 5 cold + 14 dry + 5 moist.
After ordinary arithmetic calculation, we obtain approximately II degree of heat (14:5, that is, approximately 3:1) and II degree of dryness (14:5, approximately 3:1).
Thus, we have calculated that the nature of this collection is hot and dry in the II degree.
Therefore, this collection was recommended by Ibn Sina for use in moderate chills and digestive weakness (“hot” quality), as well as in sweating, salivation, and diarrhea – (“dry” quality).
Using this calculation formula, one can change the nature of medicinal substances, bringing them to the required state.
This methodology is also used to remove the toxic properties of medicines. For example, if a poison is very “hot,” then to cool it, the poison is mixed with a medicine of “cold” nature.
Main medicinal plants and other remedies recommended by Ibn Sina in “The Canon of Medicine”
The systematic and logical nature as great virtues of “The Canon of Medicine” has been noted even by those who tended to downplay Ibn Sina’s significance in the history of medicine.
The success of “The Canon…” was due to the clarity, persuasiveness, simplicity of the description of the clinical picture of diseases, and the accuracy of therapeutic and dietary prescriptions. These features quickly created enormous popularity for “The Canon…” and ensured its author “sovereign power for five centuries in the entire medical world of the Middle Ages.”