Tradition says that the Carakasamhita was originally compiled by Agnivesa under the guidance of his preceptor Atreya several millennia ago. Then it was presented to a congregation of sages who held it to be of a very high standard and praised its author. With the passage of time, it suffered emendations and interpolations. It is said that in 800 BC (?) the scholar-physician Caraka revised the Carakasamhita in the light of the new knowledge. The Carakasamhita today is held in high esteem as the most authentic of all the extant works on the Ayurevedic system of medicine. The term Caraka is derived from the root cat meaning "to move about". Caraka propagated his knowledge and gave relief to patients by moving from place to place.
It became famous all over the world. At the beginning of the 8th century AD this work was translated into Arabic. Caraka's name appears as "Sharaka Indiansus" in the Latin translations of Avicena, Razes and Serapion. Fihrest (finished in 987 AD) mentions that Carakasamhita was translated from Sanskrit into Persian and from Persian into Arabic. Al-Beruni's chief source of medicine was the Arabic edition of Caraka.
There is however considerable confusion about the age and identity of Caraka as this name was borne by several ancient scholars. In the white branch of the Yajurveda, Caraka is described as an evil god. A1-Beruni has described the term Caraka to stand for an intelligent person. According to Kasikavrtti, Vaisampayana, a disciple of Vyasa is known as Caraka. The name Caraka is associated with Vedic, post-Vedic and even pre-Vedic sages. This is either their personal name or the name of the clan or school to which they belong. The propagator of the science of medicine and redactor of the Carakasamhita appears to be different from them. So much so that some modern scholars hold the view that Caraka and Patanjali are the names of one and the same sage. But it is obvious that Caraka preceded Patanjali.
The Carakasamhita, however does not provide any clue to the questions as to where and when Caraka lived. We have however some clues to determine his date:
On the basis of these clues, many scholars believe that Caraka redacted this work in the 8th BC. But P.V.Sharma places him at the third or second century BC, at the juncture of Maurya-Sunga periods. According to Mukhopadhyaya, Prof. Goldstucker has conclusively proved that Panini could not have flourished later than the sixth century BC. Panini wrote special sutras for Agnivesa and Caraka (Panini. Iv. 3. 107; iv.1. 105). These names must have been famous before Panini's time, otherwise he would not have written special sutra for them.
The Carakasmhita consists of 120 chapters which are distributed in 8 sections: Sutrasthana; Nidanasthana; Vimanasthana; Sarirasthana; Indriyasthana; Chikitsasthana; Kalpasthana; and Siddhisthana. Nomenclature of chapters of Caraka is based on the subject discussed in it and at times on the first word or phrase of the chapter. The important topics covered in this text are sarira or anatomy, vrtti or physiology, hetu or etiology, vyadhi or pathology, karma or therapeutics, kartr or the physician, karana or medicaments and appliances and vidhi or rules and regulations for diet, drug and regimen.
Caraka's discussion of matter bears a close identity with that of the Nyayavaisesika. Caraka believed that human body is composed of innumerable cells. They, in their turn, are composed of five mahabhutas, viz., prthvi, ap, tejas, vayu and akasa. Akasa being all-pervasive, only four mahabhutas are derived from the previous body. To this, four mahabhutas each from the sperm of the father, ovum of the mother and nutrient fluid supplied during pregnancy period are added. Thus the body is composed of 16 types of mahabhutas derived from four different sources. Of all the constituents of the body, three dosas, viz., vata, pitta and kapha (they are often wrongly rendered as wind, bile and phlegm respectively) play a vital role in normal as well as abnormal functions of the body and in the treatment of diseases. Their equipoise gives positive health, and any disturbance in the equilibrium results in disease and decay of the body. They regulate the functions of the mind also.
Caraka believed that foods and drugs as well as the body are composed of the same basic elements, viz., prthvi, ap, tejas, vayu and akasa. Body tissues are consumed during the process of work. These are to be replenished. Caraka has described agni or the enzymes required for digestion and metabolism to be responsible for the growth of the life-span, complexion, vitality, energy, plumpness, ojas, muscular strength, etc.
Caraka knew that blood circulates and gives life to different organs of the body. Heart is described as the controlling organ. Body is composed of innumerable channels, big and small. They not only supply nutrition to tissues but also take out the waste products from there. Caraka describes sperm and ovum to be composed of parts, and each part is again sub-divided. Different organs of the living being are represented in latent form in these sub-divided parts. If there is any defect in any of these sub-parts, then the corresponding organ of the child will be affected.
Caraka prescribed three important pursuits of life: longevity, wealth and also the wellbeing including salvation in the next life.
Caraka believed that diseases are caused by: 1) Intellectual blasphemy which includes immoral and anti-social activities due to the perversion of intelligence, patience and memory, that is, psychic factors; 2) Effects of time and season, that is, natural factors; and 3) Unwholesome contact with the objects of senses, that is, somatic factors. The concept of psychosomatic factors, including the natural ones, for the causation of diseases is a unique feature of Ayurveda. Twenty types of disease-causing germs are described in Caraka, some of them residing outside the body and some others inside. Various methods have been described in Caraka for the treatment of different diseases. They include oral medicines, eye drops, gargles, smoking, nasal inhalations, collyriums, ointments, creams, lotions, medicated oils and ghees, suppositories, tampons, cotton swabs, enemas, douches, fomentation, bandages, etc.
Carakasamhita describes one hundred and forty-nine important diseases. Three hundred and forty-one plants and plant products, 177 animal products and 64 minerals are described along with the properties of most of them for the treatment of diseases. Poisonous plants and animals along with the treatment of their poisoning are described in detail. Caraka has described rejuvenation therapies to prevent aging of healthy individuals and to recover patients from their convalescence state. Similarly, aphrodisiac drugs to increase virility and cure impotency are described. Caraka has laid much emphasis on proper diet and regimen by healthy individuals as well as patients.
Most interesting fact is that there is a description of air-conditioning of houses cooling in summer and heating in winter.
Caraka has completely ruled out dogmatism in the field of medicine. The following, according to him, are the criteria for drawing correct conclusions: 1) Authentic testimony; 2) Direct observation; 3) Inference; and 4) Logical reasoning
According to Caraka, a physician should have compassion for patients. He should devote himself to the treatment of patients who are curable and reject those who are incurable. Caraka suggested that the ruler of the state must be ever vigilant to protect genuine physicians and ban the practice by pseudo-physicians, failing which such quacks will endanger the life and property of the people.
The rules of admission to medical sciences were strict. Before a student was admitted for the study of the medical science he was fully examined with reference to his physical qualities and mental aptitude. He had to take the oath of initiation in the presence of respectable persons of society to lead his life in such a way as would be conductive to his study. After completion of the study he was to be further examined before getting admission to the profession.
No doubt Caraka conceived the germ theory of the causation of diseases, but he rejected the idea that germs are the only causative factors for disease. On the other hand, he had advanced the theory that it is the imbalance of dosas and vitiation of dhatus which are primary causes of diseases, and various germs may grow in the body only when they get such a congenial environment. Both for metabolic diseases and infective ones, correction of the imbalance of dosas and dhatus constitutes the basic principle of all therapeutics. This is a unique feature of the Ayurvedic concept of diseases and their management as enunciated by Caraka in his monumental work.
Surprisingly, Caraka is very modern in his emphasis on the prevention of diseases than on cure. Similarly, the theories of immunity, digestion and metabolism are quite mundane. Caraka's description of the general nursing home, maternity home, medical ethics, emphasis on experimental scientific methodology, repudiation of dogmatism, heredity and many advanced concepts of pathogenesis and management of diseases bears testimony to its relevance today.
Bag, A.K. 1997. History of Technology in India. Delhi: Indian National Academy of Science.
Mukhopadhyay, G. N. 1983. On the medical authorities. In History of Science in India ( Ed. Debiprasad Chattopadyaya). New Delhi: Editorial Enterprises.
Sharma, P.V. 1992. History of Medicine in India. Delhi: Indian National Academy of Science.