The achievements of the ancient Indians in the field of philosophy are but very imperfectly known to the world at large, and it is unfortunate that the condition is no better even in India. There is a small body of Hindu scholars and ascetics living a retired life in solitude, who are well acquainted with the subject, but they do not know English and are not used to modern ways of thinking, and the idea that they ought to write books in vernaculars in order to popularize the subject does not appeal to them. Through the activity of various learned bodies and private individuals both in Europe and in India large numbers of philosophical works in Sanskrit and Pâli have been published, as well as translations of a few of them, but there has been as yet little systematic attempt on the part of scholars to study them and judge their value. There are hundreds of Sanskrit works on most of the systems of Indian thought and scarcely a hundredth part of them has been translated. Indian modes of expression, entailing difficult technical philosophical terms are so different from those of European thought, that they can hardly ever be accurately translated. It is therefore very difficult for a person unacquainted with Sanskrit to understand Indian philosophical thought in its true bearing from translations. Pâli is a much easier language than Sanskrit, but a knowledge of Pâli is helpful in understanding only the earliest school of Buddhism, when it was in its semi-philosophical stage. Sanskrit is generally regarded as a difficult language. But no one from an acquaintance with Vedic or ordinary literary Sanskrit can have any idea of the difficulty of the logical and abstruse parts of Sanskrit philosophical literature. A man who can easily understand the Vedas. the Upani@sads, the Purânas, the Law Books and the literary works, and is also well acquainted with European philosophical thought, may find it literally impossible to understand even small portions of a work of advanced Indian logic, or the dialectical Vedânta. This is due to two reasons, the use of technical terms and of great condensation in expression, and the hidden allusions to doctrines of other systems. The tendency to conceiving philosophical problems in a clear and unambiguous manner is an important feature of Sanskrit thought, but from the ninth century onwards, the habit of using clear, definite, and precise expressions, began to develop in a very striking manner, and as a result of that a large number of technical terms began to be invented. These terms are seldom properly explained, and it is presupposed that the reader who wants to read the works should have a knowledge of them. Any one in olden times who took to the study of any system of philosophy, had to do so with a teacher, who explained those terms to him. The teacher himself had got it from his teacher, and he from his. There was no tendency to popularize philosophy, for the idea then prevalent was that only the chosen few who had otherwise shown their fitness, deserved to become fit students (adhikârî) of philosophy, under the direction of a teacher. Only those who had the grit and high moral strength to devote their whole life to the true understanding of philosophy and the rebuilding of life in accordance with the high truths of philosophy were allowed to study it.
Another difficulty which a beginner will meet is this, that sometimes the same technical terms are used in extremely different senses in different systems. The student must know the meaning of each technical term with reference to the system in which it occurs, and no dictionary will enlighten him much about the matter . He will have to pick them up as he advances and finds them used. Allusions to the doctrines of other systems and their refutations during the discussions of similar doctrines in any particular system of thought are often very puzzling even to a well-equipped reader; for he cannot be expected to know all the doctrines of other systems without going through them, and so it often becomes difficult to follow the series of answers and refutations which are poured forth in the course of these discussions. There are two important compendiums in Sanskrit giving a summary of some of the principal systems of Indian thought, viz. the Sarvadars'anasa@mgraha, and the @Sa@ddars'anasamuccaya of Haribhadra with the commentary of Gu@naratna; but the former is very sketchy and can throw very little light on the understanding of the ontological or epistemological doctrines of any of the systems. It has been translated by Cowell and Gough, but I am afraid the translation may not be found very intelligible. Gu@naratna's commentary is excellent so far as Jainism is concerned, and it sometimes gives interesting information about other systems, and also supplies us with some short bibliographical notices, but it seldom goes on to explain the epistemological or ontological doctrines or discussions which are so necessary for the right understanding of any of the advanced systems of Indian thought. Thus in the absence of a book which could give us in brief the main epistemological, ontological, and psychological positions of the Indian thinkers, it is difficult even for a good Sanskrit scholar to follow the advanced philosophical literature, even though he may be acquainted with many of the technical philosophical terms. I have spoken enough about the difficulties of studying Indian philosophy, but if once a person can get himself used to the technical terms and the general positions of the different Indian thinkers and their modes of expression, he can master the whole by patient toil. The technical terms, which are a source of difficulty at the beginning, are of inestimable value in helping us to understand the precise and definite meaning of the writers who used them, and the chances of misinterpreting or misunderstanding them are reduced to a minimum. It is I think well-known that avoidance of technical terms has often rendered philosophical works unduly verbose, and liable to misinterpretation. The art of clear writing is indeed a rare virtue and every philosopher cannot expect to have it. But when technical expressions are properly formed, even a bad writer can make himself understood. In the early days of Buddhist philosophy in the Pâli literature, this difficulty is greatly felt. There are some technical terms here which are still very elastic and their repetition in different places in more or less different senses heighten the difficulty of understanding the real meaning intended to be conveyed.
But is it necessary that a history of Indian philosophy should be written? There are some people who think that the Indians never rose beyond the stage of simple faith and that therefore they cannot have any philosophy at all in the proper sense of the term. Thus Professor Frank Thilly of the Cornell University says in his History of Philosophy , "A universal history of philosophy would include the philosophies of all peoples. Not all peoples, however have produced real systems of thought, and the speculations of only a few can be said to have had a history. Many do not rise beyond the mythological stage. Even the theories of Oriental peoples, the Hindus, Egyptians, Chinese, consist, in the main, of mythological and ethical doctrines, and are not thoroughgoing systems of thought: they are shot through with poetry and faith. We shall, therefore, limit ourselves to the study of the Western countries, and begin with the philosophy of the ancient Greeks, on whose culture our own civilization in part, rests." There are doubtless many other people who hold such uninformed and untrue beliefs, which only show their ignorance of Indian matters. It is not necessary to say anything in order to refute these views, for what follows will I hope show the falsity of their beliefs. If they are not satisfied, and want to know more definitely and elaborately about the contents of the different systems, I am afraid they will have to go to the originals referred to in the bibliographical notices of the chapters.
There is another opinion, that the time has not yet come for an attempt to write a history of Indian philosophy. Two different reasons are given from two different points of view. It is said that the field of Indian philosophy is so vast, and such a vast literature exists on each of the systems, that it is not possible for anyone to collect his materials directly from the original sources, before separate accounts are prepared by specialists working in each of the particular systems. There is some truth in this objection, but although in some of the important systems the literature that exists is exceedingly vast, yet many of them are more or less repetitions of the same subjects, and a judicious selection of twenty or thirty important works on each of the systems could certainly be made, which would give a fairly correct exposition. In my own undertaking in this direction I have always drawn directly from the original texts, and have always tried to collect my materials from those sources in which they appear at their best. My space has been very limited and I have chosen the features which appeared to me to be the most important. I had to leave out many discussions of difficult problems and diverse important bearings of each of the systems to many interesting aspects of philosophy. This I hope may be excused in a history of philosophy which does not aim at completeness. There are indeed many defects and shortcomings, and these would have been much less in the case of a writer abler than the present one. At any rate it may be hoped that the imperfections of the present attempt will be a stimulus to those whose better and more competent efforts will supersede it. No attempt ought to be called impossible on account of its imperfections.
In the second place it is said that the Indians had no proper and accurate historical records and biographies and it is therefore impossible to write a history of Indian philosophy. This objection is also partially valid. But this defect does not affect us so much as one would at first sight suppose; for, though the dates of the earlier beginnings are very obscure, yet, in later times, we are in a position to affirm some dates and to point out priority and posteriority in the case of other thinkers. As most of the systems developed side by side through many centuries their mutual relations also developed, and these could be well observed. The special nature of this development has been touched on in the fourth chapter. Most of the systems had very early beginnings and a continuous course of development through the succeeding centuries, and it is not possible to take the state of the philosophy of a particular system at a particular time and contrast it with the state of that system at a later time; for the later state did not supersede the previous state, but only showed a more coherent form of it, which was generally true to the original system but was more determinate. Evolution through history has in Western countries often brought forth the development of more coherent types of philosophic thought, but in India, though the types remained the same, their development through history made them more and more coherent and determinate. Most of the parts were probably existent in the earlier stages, but they were in an undifferentiated state; through the criticism and conflict of the different schools existing side by side the parts of each of the systems of thought became more and more differentiated, determinate, and coherent. In some cases this development has been almost imperceptible, and in many cases the earlier forms have been lost, or so inadequately expressed that nothing definite could be made out of them. Wherever such a differentiation could be made in the interests of philosophy, I have tried to do it. But I have never considered it desirable that the philosophical interest should be subordinated to the chronological. It is no doubt true that more definite chronological information would be a very desirable thing, yet I am of opinion that the little chronological data we have give us a fair amount of help in forming a general notion about the growth and development of the different systems by mutual association and conflict. If the condition of the development of philosophy in India had been the same as in Europe, definite chronological knowledge would be considered much more indispensable. For, when one system supersedes another, it is indispensably necessary that we should know which preceded and which succeeded. But when the systems are developing side by side, and when we are getting them in their richer and better forms, the interest with regard to the conditions, nature and environment of their early origin has rather a historical than a philosophical interest. I have tried as best I could to form certain general notions as regards the earlier stages of some of the systems, but though the various features of these systems at these stages in detail may not be ascertainable, yet this, I think, could never be considered as invalidating the whole programme. Moreover, even if we knew definitely the correct dates of the thinkers of the same system we could not treat them separately, as is done in European philosophy, without unnecessarily repeating the same thing twenty times over; for they all dealt with the same system, and tried to bring out the same type of thought in more and more determinate forms.
The earliest literature of India is the Vedas. These consist mostly of hymns in praise of nature gods, such as fire, wind, etc. Excepting in some of the hymns of the later parts of the work (probably about 1000 B.C.), there is not much philosophy in them in our sense of the term. It is here that we first find intensely interesting philosophical questions of a more or less cosmological character expressed in terms of poetry and imagination. In the later Vedic works called the Brâhmaf@nas and the Âra@nyakas written mostly in prose, which followed the Vedic hymns, there are two tendencies, viz. one that sought to establish the magical forms of ritualistic worship, and the other which indulged in speculative thinking through crude generalizations. This latter tendency was indeed much feebler than the former, and it might appear that the ritualistic tendency had actually swallowed up what little of philosophy the later parts of the Vedic hymns were trying to express, but there are unmistakable marks that this tendency existed and worked. Next to this come certain treatises written in prose and verse called the Upani@sads, which contain various sorts of philosophical thoughts mostly monistic or singularistic but also some pluralistic and dualistic ones. These are not reasoned statements, but utterances of truths intuitively perceived or felt as unquestionably real and indubitable, and carrying great force, vigour, and persuasiveness with them. It is very probable that many of the earliest parts of this literature are as old as 500 B.C. to 700 B.C. Buddhist philosophy began with the Buddha from some time about 500 B.C. There is reason to believe that Buddhist philosophy continued to develop in India in one or other of its vigorous forms till some time about the tenth or eleventh century A.D. The earliest beginnings of the other Indian systems of thought are also to be sought chiefly between the age of the Buddha to about 200 B.C. Jaina philosophy was probably prior to the Buddha. But except in its earlier days, when it came in conflict with the doctrines of the Buddha, it does not seem to me that the Jaina thought came much in contact with other systems of Hindu thought. Excepting in some forms of Vai@s@nava thought in later times, Jaina thought is seldom alluded to by the Hindu writers or later Buddhists, though some Jains like Haribhadra and Gu@naratna tried to refute the Hindu and Buddhist systems. The non-aggressive nature of their religion and ideal may to a certain extent explain it, but there may be other reasons too which it is difficult for us to guess. It is interesting to note that, though there have been some dissensions amongst the Jains about dogmas and creeds, Jaina philosophy has not split into many schools of thought more or less differing from one another as Buddhist thought did.
The first volume of this work will contain Buddhist and Jaina philosophy and the six systems of Hindu thought. These six systems of orthodox Hindu thought are the Sâ@mkhya, the Yoga, the Nyâya, the Vais'e@sika, the Mimâ@msâ (generally known as Pûrva Mimâ@msâ), and the Vedânta (known also as Uttara Mimâ@msâ). Of these what is differently known as Sâ@mkhya and Yoga are but different schools of one system. The Vais'e@sika and the Nyâya in later times became so mixed up that, though in early times the similarity of the former with Mimâ@msâ was greater than that with Nyâya, they came to be regarded as fundamentally almost the same systems. Nyâya and Vais'e@sika have therefore been treated together. In addition to these systems some theistic systems began to grow prominent from the ninth century A.D. They also probably had their early beginnings at the time of the Upani@sads. But at that time their interest was probably concentrated on problems of morality and religion. It is not improbable that these were associated with certain metaphysical theories also, but no works treating them in a systematic way are now available. One of their most important early works is the Bhagavadgâtâ. This book is rightly regarded as one of the greatest masterpieces of Hindu thought. It is written in verse, and deals with moral, religious, and metaphysical problems, in a loose form. It is its lack of system and method which gives it its peculiar charm more akin to the poetry of the Upani@sads than to the dialectical and systematic Hindu thought. From the ninth century onwards attempts were made to supplement these loose theistic ideas which were floating about and forming integral parts of religious creeds, by metaphysical theories. Theism is often dualistic and pluralistic, and so are all these systems, which are known as different schools of Vai@s@nava philosophy. Most of the Vai@s@nava thinkers wished to show that their systems were taught in the Upani@sads, and thus wrote commentaries thereon to prove their interpretations, and also wrote commentaries on the Brahmasûtra, the classical exposition of the philosophy of the Upani@sads. In addition to the works of these Vai@s@nava thinkers there sprang up another class of theistic works which were of a more eclectic nature. These also had their beginnings in periods as old as the Upani@sads. They are known as the S'aiva and Tantra thought, and are dealt with in the second volume of this work.
We thus see that the earliest beginnings of most systems of Hindu thought can be traced to some time between 600 B.C. to 100 or 200 B.C. It is extremely difficult to say anything about the relative priority of the systems with any degree of certainty. Some conjectural attempts have been made in this work with regard to some of the systems, but how far they are correct, it will be for our readers to judge. Moreover during the earliest manifestation of a system some crude outlines only are traceable. As time went on the systems of thought began to develop side by side. Most of them were taught from the time in which they were first conceived to about the seventeenth century A.D. in an unbroken chain of teachers and pupils. Even now each system of Hindu thought has its own adherents, though few people now care to write any new works upon them. In the history of the growth of any system of Hindu thought we find that as time went on, and as new problems were suggested, each system tried to answer them consistently with its own doctrines. The order in which we have taken the philosophical systems could not be strictly a chronological one. Thus though it is possible that the earliest speculations of some form of Sâ@mkhya, Yoga, and Mîmâ@msâ were prior to Buddhism yet they have been treated after Buddhism and Jainism, because the elaborate works of these systems which we now possess are later than Buddhism. In my opinion the Vais'e@sika system is also probably pre-Buddhistic, but it has been treated later, partly on account of its association with Nyâya, and partly on account of the fact that all its commentaries are of a much later date. It seems to me almost certain that enormous quantities of old philosophical literature have been lost, which if found could have been of use to us in showing the stages of the early growth of the systems and their mutual relations. But as they are not available we have to be satisfied with what remains. The original sources from which I have drawn my materials have all been indicated in the brief accounts of the literature of each system which I have put in before beginning the study of any particular system of thought.
In my interpretations I have always tried to follow the original sources as accurately as I could. This has sometimes led to old and unfamiliar modes of expression, but this course seemed to me to be preferable to the adoption of European modes of thought for the expression of Indian ideas. But even in spite of this striking similarities to many of the modern philosophical doctrines and ideas will doubtless be noticed. This only proves that the human mind follows more or less the same modes of rational thought. I have never tried to compare any phase of Indian thought with European, for this is beyond the scope of my present attempt, but if I may be allowed to express my own conviction, I might say that many of the philosophical doctrines of European philosophy are essentially the same as those found in Indian philosophy. The main difference is often the difference of the point of view from which the same problems appeared in such a variety of forms in the two countries. My own view with regard to the net value of Indian philosophical development will be expressed in the concluding chapter of the second volume of the present work.