The Nyaya Theory of Knowledge: A Critical study of some problems of Logic and Metaphysics

As a system of realism, the Nyëya deserves special study to show that Idealism was not the only philosophical creed of ancient India. This book is an attempt to give a complete account of the Nyëya theory of knowledge in comparison with the rival theories of other systems, Indian and Western, and critical estimation of its worth. Though theories of knowledge of the Vedënta and other schools have been partially studied in this way by some, there has as yet been no such systematic, critical and comparative treatment of the Nyëya epistemology, The importance of such a study of Indian realistic theories of knowledge can scarcely be overrated in this modern age of Realism.

The history of Indian Philosophy is a record of many different forms and types of philosophical thought. There is hardly any system in the history of Western philosophy which has not its parallel in one or other of the systems of Indian philosophy. But of the Indian systems, the Vedanta has received the greatest attention and it has sometimes passed as the only Indian system worth the name. This is but natural. The Vedanta with its sublime idealism has an irresistible appeal to the moral and religious nature of man. It has been, and will ever remain, a stronghold of spiritualism in life and philosophy. It is like one of "the great living wells, which keep the freshness of the eternal, and at which man must rest, get his breath, refresh himself." "The paragon of all monistic systems," says William James, " is the Vedanta philosophy of Hindustan." Although we have not such a sublime monism in the Nyaya, its contribution to philosophy is not really inferior in any way. In fact, the other systems-the Vedanta not excepted -have been greatly influenced by its logical and dialectical technicalities. In their later developments, all the systems consider the Naiyayika as the most powerful opponent and try to satisfy his objections. The understanding of their arguments and theories presupposes, therefore, the knowledge of the Nyaya.

As a system of realism, the Nyaya deserves special study to show that Idealism was not the only philosophical creed of ancient India. Then, as a system which contains a thorough refutation of the other schools, it should be studied before one accepts the validity of other views if only to ascertain how far those view scans satisfy the acid test of the Nyaya criticisms and deserve to be accepted. But above all, as a through going realistic view of the universe, it supplies an important Eastern parallel to the triumphant modern Realism of the West and contains the anticipations as well as possible alternatives of many contemporary realistic theories. The importance of the Nyaya is, therefore, great for the correct understanding of ancient Indian philosophy, and for the evaluation of modern Western philosophy.

The theory of knowledge is the most important part—in fact, the very foundation of the Nyaya system. This book is an attempt to give a complete account of the Nyaya theory of knowledge. It is a study of the Nyaya theory of knowledge in comparison with the rival theories of other systems, Indian and Western, and a critical estimation of its worth. Though theories of knowledge of the Vedanta and other schools have been partially studied in this way by some, there has as yet been no such systematic, critical and comparative treatment of the Nyayaepistemology. The importance of such as the study of Indian realistic theories of knowledge can scarcely be overrated in this modern age of Realism.

The scope of the book is limited to the history of the Nyaya philosophy beginning with the Nyaya-Sutra of Gautama and ending with the syncretic works of Annam Bhatta, Visvanatha and others. It does not, however, concern itself directly with the historical development of the Nyaya. There is ample evidence to show that Nyaya as an art of reasoning is much older than the Nyaya-Sutra. We find references to such an art under the names of Nyaya, and vakovakya in some of the early Upanisads like the Chandogya. (vii. 1.2) and the Subala (ii). It is counted among the up ring as or subsidiary parts of the Veda (vide Caranovyuha, ii; Nydya-Sutra.-Vrtti 1.1.1). It is mentioned under the names of anviksiki and tarkasastra in some of the oldest chapters of the Mahabharata (vide Sabha anusasana and santi parvas). We need not multiply such references. Those here given show that the Nyaya as an art or science of reasoning existed in India long before the time of Gautama, the author of the Nyaya Sutra. As a matter of fact, it has been admitted by Vatsyayana, Uddyotakara, Jayenta, Bhatta and others that Gautama was not so much the founder of the Nyaya as its chief exponent who first gave an elaborate and systematic account of an already existing branch of knowledge called Nyaya in the form of sutras or aphorisms. It is in sutras that the Nyaya was developed into a realistic philosophy on a logical basis. What was so long as mere logic or an art of debate became a theory of the knowledge of reality? It is for this reason that the present work is based on the Nyaya Sutra and its main commentaries.

The first edition of the book was exhausted in 1947. I regret very much that the second edition could not be brought out (in time owing to labour unrest and other post-war difficulties in publication, and many students and scholars were put too much inconvenience by the fact that the book was out of the market for over three years. An attempt has been made in this edition to improve the book by introducing minor changes and making necessary corrections and additions.

I am grateful to those scholars who appreciated the first edition and suggested some improvements. In this respect, I am especially indebted to the late Professor A. B. Keith who considered the book to be a very substantial contribution to the study of Indian philosophy and its method of presentation the most effective way of making Indian philosophy a real and living factor in present-day metaphysical theory. I am also thankful to the authorities of some universities in India where the book is recommended for use.

The Nyaya philosophy is primarily concerned with the conditions of valid thought and the means of acquiring a true knowledge of objects. Nyaya as a science lays down the rules and methods that are essentially, necessary for a clear and precise understanding of all the materials of our knowledge as these are derived from observation and authority. With this end in view, the science of Nyaya deals with all the processes and methods that are involved, either directly or indirectly, in the right and consistent knowledge of reality. That this is so appears clearly from the common use of the word anviksiki, as a synonym for the Nyayasastra. The name anviksiki means the science of the processes and methods of a reasoned and systematic knowledge of objects, supervening on a vague understanding of them on the basis of mere perception and uncriticised testimony. In other words, it is the science of an analytic and reflective knowledge of objects in continuation of and as an advance on the unreflective general knowledge in which we are more receptive than critical. It is the mediated knowledge of the contents of faith, feeling and intuition. Accordingly, Nyaya (literally meaning methodical study) may be described as the science of the methods and condition of valid thought and true knowledge of objects, In a narrow sense, however, Nyaya is taken to mean the syllogistic type of inference, consisting of five propositions called its members or constituents.

It should, however, be remarked here that the epistemological problem as to the methods and conditions of, Valid knowledge is neither the sole nor the ultimate concern of the Nyaya philosophy. Its ultimate end, like that of the other systems of Indian philosophy, is liberation, which is, the summum bonum of our life. This highest good is conceived the Nyaya as a state of pure existence which is free from both pleasure and pain. For the attainment of the highest end of our life, true knowledge of objects is the sure and indispensable means. Hence it is that the problem of knowledge finds an important place in the Nyaya philosophy.

But an enquiry into the conditions of valid thought and the methods of valid knowledge presupposes an account of the nature and forms of cognition or knowledge in general. It requires us also to consider the nature and method of valid knowledge in general and the nature and test of truth or validity in particular. Hence the preliminary questions that arise in the Nyaya theory of knowledge are: What is cognition or knowledge as such? What are its different forms? What is valid knowledge? What is meant by a method of valid knowledge in general? What do we mean by truth or validity? What is the test of truth, the measure of true knowledge, and the standard of validity? What are the constituents or factors of valid knowledge?

It is a matter of historical interest to note here that, among other things, the problems of, knowledge in general and those of the methods of valid knowledge in particular were brought home to the Naiyayikas by the Buddhists and other sceptical thinkers of ancient India in the course of their scathing criticism of the realistic philosophy of Gautama. They set at nought almost the whole of the Nyaya philosophy as an edifice built on sand. The Nyaya teaches that the highest good is attainable only through the highest knowledge. But the theory of knowledge in it is a vicious circle. It takes upon itself the futile task of Kant's first Critique where he examines reason in order to prove the validity of thought and reason. “If it is the business of Kant in his Critique of Pure Reason to show how mathematics is possible, whose business is it to show how the Critique of Pure Reason itself is possible?” With regard to the Nyaya theory of knowledge, a similar question is asked by the Buddha critics. It is pointed out by them that criticism of knowledge must be made by the instrument under criticism and thereby presupposes the very thing in question. Thus the validity of knowledge is made to rest on the validity of the methods of knowledge. To maintain that our knowledge is true we must prove that it is really so, that it is derived from a valid method of knowledge which always gives us true knowledge and never leads to a false idea. But, then, how are we to know the validity of that method of knowledge? From the nature of the case, the task is an impossible intellectual feat.

With regard to the knowledge of validity, there are two possible alternatives. The validity of knowledge may be cognised by itself, i.e. be self-cognised. Or, the validity of one piece of knowledge may be cognised by some other knowledge. The first alternative that knowledge cognises its own validity is inadmissible. Knowledge, according to the Nyaya, cognises objects that are distinct from and outside of itself. It cannot turn back on itself and cognise its own existence, far less its own –validity. Hence no knowledge can be the test of its own truth. The second alternative, that the validity of any knowledge is tested by some other knowledge, is not less objectionable. The second knowledge can at best cognise the first as an object to itself, i.e. as a particular existent. It cannot go beyond its object, namely, the first knowledge, and see if it truly corresponds with its own object. An act of knowledge having another for its object cognises the mere existence of the other as a cognitive fact. It cannot know the further fact of its truth or falsity. Moreover, of the two cases of knowledge, the second, which knows the first, is as helpless as the first in the matter of its own validity. It cannot, ex hypothesi, be the evidence of its own validity. Hence so long as the validity of the second knowledge is not proved, it cannot be taken to validate any other knowledge. It cannot be said that the second has self-evident validity so we do not want any proof of it. This means that one piece of knowledge, of which the validity is self-evident, is the evidence for the validity of another. But it the truth of one knowledge can be self-evident, why not that of another? Hence if the second knowledge has self-evident validity, there is nothing to prevent the first from having the same sort of self-evidence. As a matter of fact, however, all knowledge has validity only in so far as it is tested and proved by independent grounds. Truth cannot, therefore, be self-evident in any knowledge.