Avicenna's Canon of Medicine.
a precise.

Page Index.

The Material Causes
The Vital Faculty
9. The Efficient Causes
2. The Elements
6. The Psychic Faculties
10. The Formal Causes
3. The Humors
7. The Vital Force
11. The Vital Faculties
4. The Variability of the Humors
8. The organs
12. The Final Causes

Introduction.
Avicenna begins The Canon with a definition of the science of medicine: Medicine (tibb) is the science by which we learn the various states of the human body in health and when not in health, and the means by which health is likely to be lost, and when lost, is likely to be restored. In other words, medicine is the art whereby health is conserved and the art whereby it is restored after being lost.

Avicenna insists that the human body cannot be restored to health unless the causes of both health and disease are determined. In categorising the causes, he states that a complete knowledge may be, and should be obtained of the causes and antecedents of a disease, provided, of course, such causes exist. Sometimes these causes are obvious to the senses but at other times they may defy direct observation. In such circumstances, causes and antecedents have to be carefully inferred from the signs and symptoms of the disease. Hence, a description of the signs and symptoms of disease is also necessary.

There are four causes: material, efficient, formal and final:

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The Material Causes.
The material cause (maddi) is the physical body which is subject to health and disease. This may be immediate and involve the organs of the body together with their vital energies, or remote as involving the humors, or remoter than these, by involving the elements which are the basis for both structure and change (or dynamicity). Things which thus provide the foundation of health and disease, get so thoroughly altered and integrated that from an initial diversity there emerges a holistic unity with a specific structure and a specific type of temperament.
The material cause then, is the physical body, as viewed from the traditional perspective. It consists of the organs, the vital energy (thymos), the humors and the elements.

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The Elements.
The primary constituents of the human body are "the elements." They are the basic building blocks for the science of medicine.
The four elements - Earth, Air, Fire and Water - are the simplest building blocks of all that is material, including our bodies. Each of these has two qualities: Earth is dry and cold; Water, cold and moist; Air, hot and moist; and Fire is hot and dry.
The elements also have special relationships to each other: Earth is contrary to Air and Water to Fire. Union between the elements is possible because Water serves as a link between Earth and Air and Air as a link between Water and Fire.
The elements, like musical tones, possess an inclination not only to ascend and descend, but also to move in a circular direction. Each element is joined by one of its qualities to that which is below and by the other to that which is above it.
Water to Earth beneath by coldness and to Air above by moisture; Air to Water beneath by moisture and to Fire above by heat; Fire to Air beneath by heat and to Earth toward which it declines by dryness; Earth to Water above by coldness and to Fire towards which it declines by dryness.
Two of the elemental qualities are active and two passive. Active are hot and cold. Passive are dry and wet. An ideal combination of elements exists when each one is on an equitable basis with the other.
Quality results from the opposing qualities of the elements, a mixture of hot, cold, wet and dry. Balance comes when the strength of primary qualities are equal and represent an average of these qualities. In medicine, balance does not depend upon the qualities and elements being exactly equal, but upon them being "equitable," meaning that the quality and quantity of the elements are distributed in such a manner that the resulting pattern or equilibrium of the body as a whole or of its parts is the one most appropriate for that person.
The proportion in which the elements are united with the body has an influence upon action. Slow and heavy movement signifies a predominance of cold and dryness (Earth); fearfulness and sluggishness, of cold and wetness (Water); cheerfulness, of heat and wetness (Air); and sharp, angry violence, of heat and dryness (Fire).
All living beings consist of elemental qualities which are interwoven into their physical process. If something changes at an elemental level, something must have changed in the physical process. The two stand to each other in the strict relationship of cause and effect.
The phenomena of the external world and, in traditional medicine, the inner world, also consist of the elements and their qualities. Different elemental qualities are always based on the different properties of the elements (higher, lower, lighter, heavier, colder, hotter, etc.). The distinguishing characteristic of the elements is that they differ like two colours, red and green, and like two shades of a single colour, light and dark blue or like the shapes rough and square. The properties of the elements distinguish them from one another and at the same time orders them in definite ways.
The dynamic quality of the elements is that they have direction. The elements attract and in turn are attracted and are therefore directional forces. Elemental motion has its origin not in their different properties but in differences of dynamic quality as conveyors of motion.

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The Humors.
The humors are the vital essences of the body. These humors affect the function of the body and are themselves influenced by physical functions.
Food and drink are transformed into innate heat through the digestive process. The humors arise in the second stage of digestion in the liver. This process produces four humors which sustain and nourish the body and move through the channels or meridians: sanguineous (blood), serous (phlegm), bilious (choler, yellow bile) and atrabilious (melancholy, black bile); which correspond respectively to Air (hot and moist), Water (cold and moist), Fire (hot and dry) and Earth (cold and dry). The humors are subject to variation in quantity and to variation in degree of purity.
Illness results when there is either a quantitative or qualitative change of a humor. In a "normal" state, the humors are assimilated by the organs and completely integrated into the tissues. In an "abnormal" state, which is due to improper digestion, the material is unsuitable for assimilation and must therefore be eliminated by the body. Surpluses may be eliminated by exercise, bathing, coitus, purges and laxatives.

  1. The sanguineous humor (blood), which is of a balanced nature, is hot and moist, sweet and red, and exceeds the other humors in proportion to quantity. It imparts strength and colour to the body and engenders the drives. Located in the heart, it relates to the Zodiacal constellations of Leo, Aries and Sagittarius.
  2. The phlegm humor or serous humor, is next to blood as far as the relative quantity present in the body is concerned. This humor is watery, cold, moist and white and moderates the strength, heat and thickness of the blood,  nourishes the brain, and moistens and nourishes the moving parts of the body. If an abnormality of blood arises, heat will dissolve the phlegm humor into blood. Cancer, Pisces and Scorpio are the Zodiacal signs relating to this humor.
  3. The bilious humor, is less plentiful in the body than either blood or phlegm. Its quantity is hot and dry, yellow or red and bitter. A part of it passes from the liver to the gallbladder and another part flows from the liver with other humors. This humor moderates moisture and provides a penetrating quality to the blood so that it may enter more readily into every tissue of the body. The bilious humor prevents the body from becoming heavy, sleepy and dull. It penetrates and opens passages and sustains those components of the body in which the fiery element predominates. Zodiacal signs of the bilious humor are Gemini, Aquarius and Libra.
  4. The atrabilious humorís quality is earthy and gross, thick, black and sour. A part of it is separated out by the spleen and a part remains within the blood. This humor feeds the bones, the spleen and other parts of the body which are gross or "melancholy" in nature. It tempers the two hot humors (sanguineous and bilious) and restrains the vaporous volatiles that arise from blood. The atrabilious humor thickens the blood and thus prevents it from flowing too freely through the veins and arteries. The Zodiacal relationship of this humor is with Taurus, Virgo and Capricorn.

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Variability of the Humors.
The humors vary considerably as regards their quantity and quality.
The sanguineous rules from 3 am to 9 am; the bilious from 9 am to 3 pm; the phlegm humor from 3 pm to 9 pm and the atrabilious humor from 9 pm to 3 am. The sanguineous humor increases in spring. The heat of summer opens the pores, dissolves excess humors and reduces them, and causes the vital breath to escape from the body when exhaling, together with moisture and vapours. During this time, the bilious humor is dominant. Autumn tends to generate the phlegm humor. During winter the humors thicken, the sinews are contracted and the natural heat is directed inward. The atrabilious humor increases and makes people sluggish.
The activity of the elemental qualities (cold and heat) tends to determine which type of humors are most likely to form. When the amount of heat present is in balance, the sanguineous humor will be formed; when heat is in excess, the bilious humor forms; when there is such an excess of heat that oxidation occurs, the atrabilious humor forms. When the amount of cold present is balanced, the phlegm humor forms; when there is an excessive amount of cold, congelation becomes dominant and the atrabilious humor forms.

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The Temperaments.
The natural predominance of a given humor in the human body provides specific  characteristics of physique and behaviour.
Those dominated by the sanguinious humor are cheerful, courageous, kind and ingenious. Their blood, if of good quality, gives them a keen wit.
As a person accumulates fat, the amount of Phlegm present relative to blood, increases. Domination of the phlegm humor is present in people who are generally lazy, given to pleasure, and who are sleepy, idle, dull witted, heavy and slow. They love rich foods and drink.
Those with a predominance of the bilious humor are easily provoked, given to treachery and vehement in action; fierce when attacking, but inconstant in maintaining the assault; inclined to envy, pride, extravagance and vindictiveness. If there is corruption of the  bilious humor, they tend to be subject to abnormal desires and terrible nightmares.
Those dominated by the atrabilious humor are difficult, obstinate, suspicious, sorrowful and given to terrifying impulses.
The natural predominance of a given humor in the human body provides specific  characteristics of physique and behaviour.

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The Psychic Faculties.
There are three faculties (Avicenna: souls) within man, the vegetable, animal and rational. All of which fulfil their own functions. The more refined the mixture of the humors, the greater is the perfection of the faculties and the more complete the integration of the soul.Health means the harmony and total balance of the humors (eucrasia - Classical Greek.), while illness represents a disruption of the normal balance of the constitution.
Of course there is never perfect harmony, as  living things are always in a state of dynamic equilibrium in which one state of imbalance counteracts another state of imbalance; therefore health means the re- establishment of the balance of the humors relative to an individualís own constitution and environment. Diagnosis for such disorders as fever are, in fact, based on searching in order to discover in which way the humors have become unbalanced. In diseases that are associated with clear symptoms, diagnosis is made from the most notable sign or signs of the disease, and a disease will often receive its name from the main signs associated with it.

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The Vital Force.
The vital force (breath - Avicenna, pneuma or thymos - Classical Greek.) acts as the link between the body, soul and spirit. It is the role of the vital force to maintain a perfect equilibrium within the elements of the body, and between the elements of the body and the environment.
The left side of the heart is hollow in order to serve both as a storehouse of the vital force, as well as the place of manufacture of the vital force. The vital force in turn enables the soul to be convey its directions to the body and its components. In the first place the vital force is a  rallying-point for the vital faculties (of the soul), and in the second place it is an emanation that penetrates every tissue of the body.
The vital force is generated from the more refined aspects of the humors and out of vital heat, while the tissues themselves are produced from the coarser and earthy aspects  of these humors. In other words, the vital force is related to the refined particles as the body is related to the coarser particles of the same humors.
There are three aspects or spirits to the vital force, the natural spirit, the animal spirit and the vital spirit. Each of these three aspects has its own place and function and each has its own particular temperament.
Although the body consists of several organs, there is one from which they all originally arose. As to what this organ actually was, there are various opinions. The fact remains that one organ necessarily came to light before other organs could arise out of it. Exactly the same is true in the case of the vital force, there is one single vital force that accounts for the origin of the other vital energies. This vital force, according to the most important philosophers, arises in the heart, passes thence into the principal centers of the body, lingering in them long enough to enable them to impart to it their respective temperamental properties. While it remains in the cerebrum it receives a temperament that enables it to respond to the impulses of sensation and movement; in the liver, it receives the drive of nutrition and growth (vegetative drives); in the generative glands it acquires a temperament that enables it to respond to the impulse of generation (reproduction).

Thus the vital force has three components:

  1. The vital spirit, which is hot and dry, has its centre in the left ventricle of the heart, preserves life, causes the body to grow, move and reproduce, and travels through the arteries.
  2. The psychic spirit, which is cold and moist, has its centre in the brain, causes sensation and movement, travels through the nerves and is the source of movement and reason.
  3. The natural spirit, which is hot and moist, has its centre in the liver, is concerned with the reception of food, growth and reproduction and travels through the veins.

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The Organs.
The humors are the constituent elements from which the organs of the body are formed,  just as the humors are derived primarily from the intercombination of nutrients and the nutrients are primarily composed of a combination elements.
The organs are divided into two types: simple organs, which have homogeneous parts such as flesh, bones and nerves, and compound organs such as the hands and face. The organs are the servants of the mind and are the instruments by the which the mind can control the body.
The primary elemental quality of an organ is based on its nutrient while its secondary quality is determined by what it excretes.

  1. Hot organs consist of vital force; blood; and tissues of the heart, liver, flesh, muscle, spleen, kidneys, breasts, testicles, muscular coats of arteries, veins, and of skin of the palm.
  2. Cold organs consist of phlegm; and tissues such as hair, bones, cartilage, ligaments, serous membranes, nerves, spinal cord, brain, solid and liquid fats and skin.
  3. Moist organs consist of phlegm; blood; and tissues such as sold and liquid fats, brain, spinal cord, breast, testicles, lungs, liver, spleen, kidneys, muscles and skin.
  4. Dry organs consist of tissues such as hair, bones, cartilage, ligaments, tendons, membranes, arteries, veins, motor nerves, heart, sensory nerves, and skin.

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The Efficient Causes.

The efficient causes (failiya) are capable of either preventing or inducing change in the human body. They may be external to the person or be of internal origin. External causes are: age, sex, occupation, residence and climate and other agents which effect the human body by contact, whether contrary to nature or not. Internal causes are sleep and wakefulness, evacuation of secretions and excretions, the changes at different periods of life in occupation, habits and customs, ethnic group and nationality.
The efficient causes are clear and vary with each individual. Whereas the elements, humors, vital force and organs are all inherent and from nature, the efficient causes are acquired and develop out of the nurturing process.

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The Formal Causes.
There are three formal causes (suriyah): temperaments (mizajat), the faculties or drives (qawa) which emerge from it, and the structure.
Temperament arises from the elements and humors and it determines the way in which the individual functions. Each kind of living creature, as well as every organ of the body, has its own temperament which is perfectly suited to its own functional requirement. Some are more hot, others more cold, others more dry and others more moist.
The temperament is "equable" (balanced or in eucrasia - Classical Greek) when the contrary qualities are in perfect equilibrium, and out of harmony or "inequable" when the temperament tends toward a particular quality.
Therapeutics, then, are based on the principle of providing treatments or medicines that have the opposite quality to the excess of the imbalance. That is, "cold" diseases can be cured by "hot" remedies and vice versa.
It is worth remembering that when a medicine is referred to as being temperate (balanced - Avicenna), it does not mean that its temperament is the same as of a human being, or that it is even similar to it, for it would then be like a human being. It merely means that such a medicine, after having been acted upon by the innate heat [metabolised], fails to produce any material change in the normal state of the body, and that its pharmacological actions remain within the limits of the normal human temperament. In other words, when this medicine is given to a normal person, it does not produce any appreciable change or imbalance in the body.
When it is said that a medicine is hot or cold, it does not mean that the physical quality of the medicine is particularly hot or cold or that it is colder or hotter than the human body. It just means that such a medicine, when ingested or applied, produces a greater amount of heat or cold than what was originally present in the body. A medicine which, for example, is cold for a human being may be hot for a scorpion, while a medicine which is hot for the human being may be cold for a serpent. In fact it may also mean that the same medicine may be less hot for one person than for another. This is the reason why physicians are advised to change their medicine when it fails to produce the desired result.
The growth and decay of the human body is dependent upon the human temperament. Growth depends upon the heat contained in the inherent generative energy, which is gradually used up. Meanwhile, the moisture lessens in quantity and quality, thus preserving the innate heat at a constant level up to the old age. Ultimately, however, the moisture of the body comes to an end, and the innate heat is extinguished, thus causing the death to which everyone is destined and the timing of which depends upon the original temperament of the human body.
The uniqueness of the temperament of each individual indicates that each individual is a microcosm that represents a world of its own, which is not identical with any other microcosm. Yet, the repetition of the same basic humors in each constitution bears out the fact that each microcosm presents a morphological resemblance to other microcosms.
Moreover, there is an analogy between the human body and the cosmic order, as shown by the correspondence between the humors and elements. There is in the Hermetico-alchemical natural philosophy, which has always been closely tied to Graeco-Arabic medicine, which represents a basic doctrine of the correspondence between all the various orders of reality: the intelligible hierarchy, the heavenly bodies, the order of numbers, the parts of the body, the letters of the alphabet which are the "elements" of the Sacred Book, etc. The seven cervical and the twelve dorsal vertebrae correspond to the seven planets and the twelve signs of the Zodiac, as well as to the days of the week and the months of the year; and the total number of discs of the vertebrae, which are considered to be twenty-eight, to the stations of the moon. There is, therefore, both numerical and astrological symbolism connected with medicine.
Thus these correspondences and "sympathy" (sympathia - Classical Greek) between various orders of cosmic reality, form the philosophical background of Graeco-Arabic Medicine.

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The Vital Faculties.
The body also possesses vital faculties or drives, from which originate the functions of various organs. The major faculties are:

  1. the vital faculty (hayawaniyah), which is responsible for preserving the integrity of the vital force, sensation, and movement of the heart;
  2. the natural faculty (tabiiyah), which governs the nutritive powers of the liver and the reproductive powers of the generating organs; and
  3. the animal faculty (nafsaniyah), which controls the brain and the rational faculty.

The ability of the different components of the body to function as one entity arises from the vital faculty, which provides the body with its inner force. The vital faculty is that which appears in the vital force at the very moment at which the vital force develops out of the rarefied particles of the humors.
There is a relationship between the human body as a whole and its component parts; the whole being is active in any part or components, while any part or component continually demonstrates its relationship to the whole. Whenever we encounter a phenomenon that shows this kind of relationship between its totality and its component parts, we may assume that there is an ordered action of forces that underpins its existence. This is the role of the faculties which we can only know through their effects, as it works through the physical body without ever being confined by it.

(Special note: according to some of Avicennaís other writings, the faculties represent the natural laws inherent in the elements, humors and in the vital force. In the true Hermetic tradition, Avicenna sees these natural laws as embodying a component of Divine creative perfection, which to him explains the tendency inherent in natural systems to direct themselves towards a  point of balance or equilibrium.- P.H.)

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The Final Causes.
The final causes (tamamia) are the actions or functions. They can only be understood from a knowledge of both the faculties or drives (qawa) and the vital energies (arwah) that are ultimately responsible for them.
 

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