The Canon of Medicine

This article is about The encyclopedia compiled by Avicenna. For other uses, see Unani.

Avicenna
Avicennism
The Canon of Medicine
The Book of Healing
Hayy ibn Yaqdhan
Criticism of Avicennian philosophy
Unani medicine

Persian version of The Canon of Medicine located at tomb of Avicenna in Hamedan

The Canon of Medicine (Arabic: القانون في الطب‎ al-Qānūn fī al-Ṭibb) is an encyclopedia of medicine in five books compiled by Ibn Sīnā (Avicenna) and completed in 1025. It presents a clear and organized summary of all the medical knowledge of the time. It is the most influential Galenic document of the Middle Ages Originally written in the Arabic language, the book was later translated into a number of other languages, including Persian, Latin, Chinese, Hebrew, German, French, and English with lots of commentaries. The Canon is considered one of the most famous books in the history of medicine.

Canon from Latin canōn, from Ancient Greek κανών (kanón, “measuring rod, standard”), akin to κάννα (kanna, “reed”), perhaps from Semitic (compare Arabic قانون (Qānūn, “law”) Hebrew קנה (qaneh, “reed”)). also Qanun, means "law" in Arabic, Persian, Urdu and Turkish (spelled as Kanun), the Canon of Medicine remained a medical authority for centuries. It set the standards for medicine in Medieval Europe and the Islamic world, and is Avicenna's most renowned written work. Qanun was used at many medical schools—at University of Montpellier, France, as late as 1650. Much of the book was also translated into Chinese as the Huihui Yaofang (Prescriptions of the Hui Nationality) by the Hui people in Yuan China. The Canon is used in Unani (Ionian) medicine, a form of traditional medicine practiced in India. The principles of medicine described by the Canon ten centuries ago are still taught at UCLA and Yale University, among others, as part of the history of medicine.^{[citation needed]}

George Sarton, the father of the history of science, wrote in the Introduction to the History of Science:

"One of the most famous exponents of Muslim universalism and an eminent figure in Islamic learning was Ibn Sina, known in the West as Avicenna (981-1037). For a thousand years he has retained his original renown as one of the greatest thinkers and medical scholars in history. His most important medical works are the Qanun (Canon) and a treatise on Cardiac drugs. The 'Qanun' is an immense encyclopedia of medicine. It contains some of the most illuminating thoughts pertaining to distinction of mediastinitis from pleurisy; contagious nature of phthisis; distribution of diseases by water and soil; careful description of skin troubles; of sexual diseases and perversions; of nervous ailments."

Influence in Western world

A Latin copy of the Canon of Medicine, dated 1484, located at the P.I. Nixon Medical Historical Library of the University of Texas Health Science Center at San Antonio.

The Qanun was translated into Latin as Canon medicinae by Gerard of Cremona in the 12th century. Henceforth the Canon served as the chief guide to medical science in the West and is said to have influenced Leonardo da Vinci^{[citation needed]}. Its encyclopaedic content, its systematic arrangement and philosophical plan soon worked its way into a position of pre-eminence in the medical literature of Europe, displacing the works of Galen and becoming the text book for medical education in the schools of Europe. The text was read in the medical schools at Montpellier and Leuven as late as 1650, and Arnold C. Klebs described it as "one of the most significant intellectual phenomena of all times."^{[citation needed]} In the words of Dr. William Osler, the Qanun has remained "a medical bible for a longer time than any other work".

The first three books of the Latin Canon were printed in 1472, and a complete edition appeared in 1473. In the last 30 years of the 15th century it passed through 15 Latin editions. In recent years, a partial translation into English was made.

The influential Canadian physician, Sir William Osler, described the Canon as "the most famous medical textbook ever written" noting that it remained "a medical bible for a longer time than any other work." In 2006, Professor John Urquhart noted the relevance of the Canon to modern medicine, comparing it to an influential medical work of the 19th century, The Principles and Practice of Medicine (1892) by Osler himself, and concluded:

"If the year were 1900 and you were marooned and in need of a guide for practical medicine, which book would you want by your side?" My choice was Ibn Sina. A leading reason is that Ibn Sina gives an integrated view of surgery and medicine, whereas Osler largely shuns intervention. Ibn Sina, for example, tells how to judge the margin of healthy tissue to take with an amputation, a basic topic uncovered by Osler. The gap between medicine and surgery is now closing, with the advent of interventional cardiology, gastroenterology, radiology, etc. Ibn Sina correctly saw medicine and surgery as one.

Mona Nasser Aida Tibi and Emilie Savage-Smith note: "The enduring respect in the 21st century for a book written a millennium earlier is testimony to Ibn Sina's achievement."

Overview

The book explains the causes of health and disease. Ibn Sina believed that the human body cannot be restored to health unless the causes of both health and disease are determined. He defined medicine (tibb) as follows:

"Medicine is the science by which we learn the various states of the body; in health, when not in health; the means by which health is likely to be lost; and, when lost, is likely to be restored. In other words, it is the art whereby health is concerned and the art by which it is restored after being lost."

Avicenna regarded the causes of good health and diseases to be:

1. The Material Causes
2. The Elements
3. The Humors
4. The Variability of the Tumors
5. The Temperaments
6. The Psychic Faculties
7. The Vital Force
8. The Organs
9. The Efficient Causes
10. The Formal Causes
11. The Vital Faculties
12. The Final Causes

The Qanun distinguishes mediastinitis from pleurisy and recognises the contagious nature of phthisis (tuberculosis of the lung) and the spread of disease by water and soil. It gives a scientific diagnosis of ankylostomiasis and attributes the condition to an intestinal worm. The Qanun points out the importance of dietetics, the influence of climate and environment on health, and the surgical use of oral anaesthetics. Ibn Sina advised surgeons to treat cancer in its earliest stages, ensuring the removal of all the diseased tissue. The Qanun 's materia medica considers some 800 tested drugs, with comments on their application and effectiveness. He recommended the testing of a new drug on animals and humans prior to general use.

The earliest known copy of volume 5 of the Canon of Medicine dated 1052 is held in the collection of the Aga Khan and is to be housed in the Aga Khan Museum planned for Toronto, Ontario, Canada.

Book 1 part 1 Humours and temperaments

Four Humours

The Canon of Medicine is based upon the Four Humours of Hippocratic medicine, but refines in various ways. In disease pathogenesis, for example, Avicenna "added his own view of different types of spirits (or vital life essences) and souls, whose disturbances might lead to bodily diseases because of a close association between them and such master organs as the brain and heart An element of such belief is apparent in the chapter of al-Lawa" (see Cardiology section), which relates "the manifestations to an interruption of vital life essence to the brain." He combined his own view with that of the Four Humours to establish a new doctrine to explain the mechanisms of various diseases in another work he wrote, Treatise on Pulse

“From mixture of the four [humors] in different weights, [God the most high] created different organs; one with more blood like muscle, one with more black bile like bone, one with more phlegm like brain, and one with more yellow bile like lung.

[God the most high] created the souls from the softness of humors; each soul has it own weight and amalgamation. The generation and nourishment of proper soul takes place in the heart; it resides in the heart and arteries, and is transmitted from the heart to the organs through the arteries. At first, it [proper soul] enters the master organs such as the brain, liver or reproductive organs; from there it goes to other organs while the nature of the soul is being modified in each [of them]. As long as [the soul] is in the heart, it is quite warm, with the nature of fire, and the softness of bile is dominant. Then, that part which goes to the brain to keep it vital and functioning, becomes colder and wetter, and in its composition the serous softness and phlegm vapor dominate. That part, which enters the liver to keep its vitality and functions, becomes softer, warmer and sensibly wet, and in its composition the softness of air and vapor of blood dominate.

In general, there are four types of proper spirit: One is brutal spirit residing in the heart and it is the origin of all spirits. Another – as physicians refer to it – is sensual spirit residing in the brain. The third – as physicians refer to it – is natural spirit residing in the liver. The fourth is generative – i.e. procreative – spirits residing in the gonads. These four spirits go-between the soul of absolute purity and the body of absolute impurity.”

Four Temperaments

The Canon also adopted the ancient theory of Four Temperaments and extended it to encompass "emotional aspects, mental capacity, moral attitudes, self-awareness, movements and dreams." It summarized Avicenna's own theory of four temperaments in a table presented as follows:

Avicenna's four primary temperaments
Evidence	Hot	Cold	Moist	Dry
Morbid states	inflammations become febrile	fevers related to serious humour, rheumatism	lassitude	loss of vigour
Functional power	deficient energy	deficient digestive power	difficult digestion
Subjective sensations	bitter taste, excessive thirst, burning at cardia	Lack of desire for fluids	mucoid salivation, sleepiness	insomnia, wakefulness
Physical signs	high pulse rate, lassitude	flaccid joints	diarrhea, swollen eyelids, rough skin, acquired habit	rough skin, acquired habit
Foods & medicines	calefacients harmful, infrigidants beneficial	infrigidants harmful, calefacients beneficial	moist articles harmful	dry regimen harmful, humectants beneficial
Relation to weather	worse in summer	worse in winter		bad in autumn

Book 1 part 2 general Anatomy and physiology

Writings on anatomy in the Canon are scattered throughout the text in sections regarding to illnesses related to certain body parts. The Canon included numerous discussions on anatomy and diagrams on certain body parts, including the first diagrams of the cranial sutures.

Blood pressure

Avicenna dedicated a chapter of the Canon to blood pressure. He was able to discover the causes of bleeding and haemorrhage, and discovered that haemorrhage could be induced by high blood pressure because of higher levels of cholesterol in the blood. This led him to investigate methods of controlling blood pressure.

Dissection

The Canon distinguished anatomy "from other aspects of medicine by its need for a different methodology." It thus stated:

"As for the parts of the body and their functions, it is necessary that they be approached through observation (hiss) and dissection (tashrih), while those things that must be conjectured and demonstrated by reason are diseases and their particular causes and their symptoms and how disease can be abated and health maintained."

Neuroanatomy and neurophysiology

Avicenna discovered the cerebellar vermis—which he named "vermis"—and the caudate nucleus, which he named "tailed nucleus" or "nucleus caudatus". These terms are still used in modern neuroanatomy and neurophysiology.

The Canon was also the earliest text to note that intellectual dysfunctions were largely due to deficits in the brain's middle ventricle, and that the frontal lobe of the brain mediated common sense and reasoning.

Ophthalmology

The contributions of the Canon to ophthalmology in medieval Islam include its descriptions and explanations on the physiology of eye movements, which still forms a basis of information for modern ophthalmology. He also provided useful information on the optic nerves, iris, and central and peripheral facial paralyses.

Another contribution the Canon made to ophthalmology was the suggestion that "the optic nerves did cross."

Book 2 (materia medica)

The Canon described no less than 700 preparations of medications, their properties, mode of action and their indications. He devoted a whole volume to simple and compound drugs in The Canon of Medicine. It credits many of them to a variety of Arabic, Greek and Indian authors, and also includes drugs imported from China, along with many of Ibn Sina's own contributions. Using his expertise, he was often critical of the descriptions given by previous authors and revised many of their descriptions. In inhalational drug therapy, the Canon described the inhalation of essential oils from pine and eucalyptus to alleviate respiratory symptoms. Both of these compounds are still present in modern-day proprietary inhalational medicines.

The Canon of Medicine deals with evidence-based medicine, experimental medicine, clinical trials, randomized controlled trials, efficacy tests, risk factor analysis, and the idea of a syndrome in the diagnosis of specific diseases.

According to A. C. Crombie, the Canon contained "a set of seven rules that laid down the conditions for the experimental use and testing of drugs" which were "a precise guide for practical experimentation" in the process of "discovering and proving the effectiveness of medical substances based in part on Galen." The emphasis of the Canon on tested medicines laid the foundations for an experimental approach to pharmacology. The Canon laid out the following rules and principles for testing the effectiveness of new drugs and medications, which still form the basis of clinical pharmacology and modern clinical trials:

1. "The drug must be free from any extraneous accidental quality."
2. "It must be used on a simple, not a composite, disease."
3. "The drug must be tested with two contrary types of diseases, because sometimes a drug cures one disease by Its essential qualities and another by its accidental ones."
4. "The quality of the drug must correspond to the strength of the disease. For example, there are some drugs whose heat is less than the coldness of certain diseases, so that they would have no effect on them."
5. "The time of action must be observed, so that essence and accident are not confused."
6. "The effect of the drug must be seen to occur constantly or in many cases, for if this did not happen, it was an accidental effect."
7. "The experimentation must be done with the human body, for testing a drug on a lion or a horse might not prove anything about its effect on man."

The Canon lists 800 tested drugs, including plant and mineral substances, with comments on their application and effectiveness. For each one, he described their pharmaceutical actions from a range of 22 possibilities (including resolution, astringency and softening), and their specific properties according to a grid of 11 types of diseases.

Inductive logic

While Ibn Sina often relied on deductive reasoning in The Book of Healing and other writings on logic in Islamic philosophy, he used a different approach in The Canon of Medicine. This text contributed to the development of inductive logic, which it used to develop the idea of a syndrome in the diagnosis of specific diseases. The Canon of Medicine was the first to describe the methods of agreement, difference and concomitant variation which are critical to inductive logic and the scientific method.

Book 3

Book 3 is arranged from head to toe covering the function and diseases of each organ.

Book 4

Book 4 covers diseases that affect the whole body like fevers.

See also

• Avicenna
  • Avicennism
  • The Book of Healing
  • Unani
• Ibn al-Nafis
  • Commentary on Anatomy in Avicenna's Canon
• Abu al-Qasim al-Zahrawi
  • Al-Tasrif
• Medical literature

External links

• Biography of Avicenna
• A scanned copy of "Kitab alQanun fi alTibb" (Book (of) the Canon of Medicine)