Ayurveda is the most ancient of all medical sciences. It is the only medical science which has withstood the ravages of time and is still thriving steadily and triumphantly even amidst the modern medical sciences of the West. It is a rich heritage handed down to us by the ancient Hindu sages of divine insight and unlimited experience. Like Hindu sages of divine insight and unlimited experience. Like Hindu philosophy, it is a vast storehouse of knowledge and even in this age of rapidly progressing sciences it can fairly boast of imparting knowledge of things unknown to them. It is for this reason that from time to time savants, both Indian and European, had been attracted to it and had made special studies of the System of Hindu Medicine. These scholars had studied Ayurveda from different points of view, from the point of view of its history, its anatomy and surgery, its gynecology and midwifery, its chemistry, its therapeutics, etc, - and had written some excellent treatises on the particular branch of Ayurveda they were interested in; but none of them had studied Ayurveda from the physiological point of view. The reason of this, I think, is that none of these scholars was a practitioner of Ayurveda. It is only a practising Kaviraja or Ayurvedic physician who has to study Ayurveda in its physiological aspect leading to the study of the nature and function of Vayu, Pitta and Kopha or Tridosa as they are comprehensively called. The others may have an academic interest in the anatomy, chemistry or history of Hindu Medicine, but an intimate knowledge of the Tridosa is essential and indispensable to an Ayurvedic physician and without this knowledge it will not be possible for him to enter into and understand the intricate problems and methods of his science and be thereby in a position to succeed in its proper, useful and practical application.
We are being repeatedly told by prominent public men and by those who practise western medicine and even by some of our modern exponents of Hindu medicine that to further the interest of Ayurveda it is necessary that it should be studied from the view point of modern science and that some of the new ideas be incorporated in it. I do not deny the utility of an elementary knowledge of the modern sciences and of modern anatomy for every student of Ayurveda. In fact, a through knowledge of the structure of the human body is essential and is enjoined by Susruta for those who wish to practise surgery. But, is the knowledge of modern physiology essential for an Ayurvedic student? The physiology of western medicine is quite different from that of Hindu medicine, which is the physiology of Vayu, Pitta and Kapha. Modern physiology may help an Ayurvedic student to some extent in the study of his subject, (I am not sure whether it may not mislead him in some instances), but hat is more necessary for him is a study of the physiology underlying his own system of medicine.
"For the successful treatment of diseases according to any system of medicine, one must have a sound knowledge of the physiology and, what is more to the point, of pathology according to that system. So anybody who professes to practise Hindu Medicine must get to know the Tridosa. But to know the three Dosas, it is less than useless to study them from the point of view of modern science alone. To thoroughly understand the real meaning of what of old Ayurvedists have told us about Vayu, Pitta and Kapha, we must study the subject from their view point. That is a very difficult task now. I have myself personally felt that difficulty when studying Ayurveda. Steeped as we are from our very childhood in ideas of the West, - imbued with the ideas of western science, - our whole outlook is vitiated, the viewpoints of the ancient Ayurvedists and of the Hindu philosophers become obscure and we fail to grasp the real meaning of their writings. It is for this very difficulty that we, of newer generations, do not know of Vayu, Pitta and Kapha what Caraka and Susruta or even Vagbhata did. The fault is not the fault of the science of Ayurveda it is entirely ours. So I would say to our critics, 'Don't judge Ayurveda by the modern practitioners of that science of medicine just as a European professors of a missionary college once told us, 'Don't judge Christianity by the present-day followers of Christ'.
"The charge is very often leveled against Ayurveda that is not scientific; and that charge is made without even knowing anything about Ayurveda. I have given ample proofs (in this book) to disprove this charge. I have shown how from the basis of the Pancabhautika theory of matter, the Ayurvedists had developed step by step the principle of Vayu, pitta and Kapha, When once they had postulated this principle they had naturally had to speak of the functions of the body in terms of Vayu, Pitta and Kapha. And this they did very elaborately ad thus created the physiology and pathology of Ayurveda by means of which they could accurately diagnose a disease. Not only this; in order to minister to the different ailments of the human body, they had to find out different medicines. And so after propounding the Principle of the Tridosa, they had, as logical sequence, had to find out the properties ad actions of a vast number of vegetable, mineral and animal products with special reference to Vayu, Pitta and Kapha. That is why, in Ayurveda, we find the properties of every kind of food and medicine described with reference to Vayu, Pitta and Kapha and we find the mention of Rasa, Virya and Vipaka of different substances and the relation of the six Rasas with the three Dosas".
"Medicine can never be a perfect science like mathematics. It is an experimental science and so will always be partly empirical. The medical man has to deal with the living human body with all its complexities ad vagaries of behaviour. He has ultimately to depend upon the human subject and not on any lower animal for his experiments. So after all, the result of a clinical study is the most important. And herein lies the excellence of Ayurveda. The conclusions arrived at by the old Ayurvedists regarding the properties and actions of drugs upon the human body were made after innumerable clinical experiments, because they had ample opportunity and a vast field for research at their disposal. What we learn in Ayurveda is the result of experience which does not cover a few years or decades only; it is the experienced knowledge accumulated over centuries and centuries. The supremacy of Ayurveda is due not to any potent indigenous drug, but to the application of that drug is conformity with the Principle of Vayu, Pitta and Kapha. The essential thing now, therefore, is to dive deep into the subject of the Tridosa, and this should be done not by blindly following the methods of modern science, but by emulating the methods of the ancient Ayurvedists; for, it is by so doing that we can get to know the real meaning of Vayu, Pitta and Kapha."
No serious attempt had yet been made to present this fundamental principle underlying the System of Hindu Medicine in a form which could be understood by student s of the Western Systems of Medicine. To this end I had engaged myself in a special study of the Vayu, Pitta and Kapha of Ayurveda and had written several articles on the subject. A this time a notifications dated the 1st November 1932, was issued by the Registrar, University of Madras, declaring a prize called the 'Sir J. C. Bose Prize" to be awarded to the writer of the best monograph on "A Critical Study of Hindu Medicine," and inviting competitors from all parts of India. As all my materials were ready, I chose "The Principle of Tridosa in Ayurveda" as the subject of my monograph which I submitted on the 25th April, 1933. On the recommendation of the committee appointed for the purpose of adjudicating on the theses submitted for the above prize, the Syndicate of the Madras University awarded the prize to me and their decision was communicated to e by the Registrar of that University by a letter dated the 2nd June, 1936. After this, many of my friends and pupils requested me to publish the thesis as there was really a want of such publications. Their special requests and persuasions are responsible for this publication of my thesis in book-form.
In publishing the book, I have re-written several chapter and added new ones of which chapter 16 on Heredity and Temperament and chapters 18,19 and 21 deserve special mention. I have also appended full Sanskrit Text which form about half the volume of the book. I have collected these from the different Ayurveda Samhitas and arranged them in methodical order. I do not claim these collections to be exhaustive, but I do hope that they will be of particular help to those who, in future, will want to pursue the subject further. Several points which were not dealt with in the book have been indicated by head-lines in the Sanskrit Texts.
In preparing my monograph, I had to consult not only the various books on Ayurveda and the extant commentaries on the different Samhitas but had also had to freely consult the standard textbooks on modern physiology. I hereby acknowledge my indebtedness to the authors of these books, specially to Dr. Mc Kendrick from whose little book on physiology (Home University Library) I have quoted several passages. Some of the diagrams included in the book have been taken with slight modifications, where necessary, from these books. In writing the first portion of my monograph, I got much help from the following books, - (1) Osteology by Dr. Hoernle, (2) Positive Sciences of the Ancient Hindus by Dr. Sir B.N. Seal, (3) Six Systems of India Philosophy by Dr. Max Muller, (4) Vaisesika Sutras edited by Major B.D. Basu, (5) Indian Philosophy by Prof. Radhakrishnan and (6) History of Indian Philosophy by Prof. S.N. Das Gupta. Dr. Seal's book and that valued portion of Dr. Das Gupta's book which deals with Ayurveda were also of ample help to me regarding Tridosa.
Of the diagrams, Fig.7 is the outcome of my own original conception. Fig.5 had been drawn by me for one of my articles in the "Prakrti" and I hereby tender my thanks to its editor, Dr. S.C. Law, for kindly lending me the block.
In conclusion, I want to make a special mention of my indebtedness to Kaviraja Dvarakanatha Sena, Kavya Vyakarava-Tarkatirtha of Calcutta – an Ayurvedist of the old orthodox school, an erudite scholar of the Nyaya system of philosophy and author of the original Sanskrit book "Dosa-siddhanta". It is no exaggeration to say that without his helpful suggestions this monograph could not have been written; in fact, I owe a great deal to him for the idea contained in Chap VI. My thanks are also due to my brother Mr. Sailendra Nath Ray, M.A., B.L. for helping me throughout with the reading of the proofs.
In a book of this nature, it is quite possible that errors may creep in. I crave, therefore, the indulgence of scholars and scientists in this respect and shall be grateful if such mistakes are pointed out to me. The subject is a complicated one and criticisms and suggestions from scholars will be really helpful.