Before dealing with the Vedanta system it seems advisable to review the general attitude of the schools already discussed to the main philosophical and epistemological questions which determine the position of the Vedanta as taught by S'a@nkara and his school.
The Sautrantika Buddhist says that in all his affairs man is concerned with the fulfilment of his ends and desires (_puru@sadrtka_). This however cannot be done without right knowledge (_samyagjnana_) which rightly represents things to men. Knowledge is said to be right when we can get things just as we perceived them. So far as mere representation or illumination of objects is concerned, it is a patent fact that we all have knowledge, and therefore this does not deserve criticism or examination. Our enquiry about knowledge is thus restricted to its aspect of later verification or contradiction in experience, for we are all concerned to know how far our perceptions of things which invariably precede all our actions can be trusted as rightly indicating what we want to get in our practical experience (_arthapradpakatva_). The perception is right (_abhranta_ non-illusory) when following its representation we can get in the external world such things as were represented by it (_sa@mvadakatva_). That perception alone can be right which is generated by the object and not merely supplied by our imagination. When I say "this is the cow I had seen," what I see is the object with the brown colour, horns, feet, etc., but the fact that this is called cow, or that this is existing from a past time, is not perceived by the visual sense, as this is not generated by the visual object. For all things are momentary, and that which I see now never existed before so as to be invested with this or that permanent name. This association of name and permanence to objects perceived is called _kaipana_ or _abhilapa_. Our perception is correct only so far as it is without the abhilapa association (_kalpanapo@dha_), for though this is taken as a part of our perceptual experience it is not derived from the object, and hence its association with the object is an evident error. The object as unassociated with name--the nirvikalpa--is thus what is perceived. As a result of the pratyak@sa the manovijnana or thought and mental perception of pleasure and pain is also determined. At one moment perception reveals the object as an object of knowledge (_grahya_), and by the fact of the rise of such a percept, at another moment it appears as a thing realizable or attainable in the external world. The special features of the object undefinable in themselves as being what they are in themselves (_svalak@sa@na_) are what is actually perceived (_pratyak@savi@saya_) [Footnote ref 554]. The _prama@naphala_ (result of perception) is theideational concept and power that such knowledge has of showing the means which being followed the thing can be got (_yena k@rtena artha@h prapito bhavati_). Prama@na then is the similarity of the knowledge with the object by which it is generated, by which we assure ourselves that this is our knowledge of the object as it is perceived, and are thus led to attain it by practical experience. Yet this later stage is prama@naphala and not prama@na which consists merely in the vision of the thing (devoid of other associations), and which determines the attitude of the perceiver towards the perceived object. The prama@na therefore only refers to the newly-acquired knowledge (_anadhigatadhigant@r_) as this is of use to the perceiver in determining his relations with the objective world. This account of perception leaves out the real epistemological question as to how the knowledge is generated by the external world, or what it is in itself. It only looks to the correctness or faithfulness of the perception to the object and its value for us in the practical realization of our ends. The question of the relation of the external world with knowledge as determining the latter is regarded as unimportant.
The Yogacaras or idealistic Buddhists take their cue from the above-mentioned Sautrantika Buddhists, and say that since we can come into touch with knowledge and knowledge alone, what is the use of admitting an external world of objects as the data of sensation determining our knowledge? You say that sensations are copies of the external world, but why should you say that they copy, and not that they alone exist? We never come into touch with objects in themselves; these can only be grasped by us simultaneously with knowledge of them, they must therefore be the same as knowledge (_sahopalambhaniyamat abhedo nilataddhiyo@h_); for it is in and through knowledge that external objects can appear to us, and without knowledge we are not in touch with the so-called external objects. So it is knowledge which is self-apparent in itself, that projects itself in such a manner as to appear as referring to other external objects. We all acknowledge that in dreams there are no external objects, but even there we have knowledge. The question why then if there are no external objects, there should be so much diversity in the forms of knowledge, is not better solved by the assumption of an external world; for in such an assumption, the external objects have to be admitted as possessing the infinitely diverse powers of diversely affecting and determining our knowledge; that being so, it may rather be said that in the beginningless series of flowing knowledge, preceding knowledge-moments by virtue of their inherent specific qualities determine the succeeding knowledge-moments. Thus knowledge alone exists; the projection of an external word is an illusion of knowledge brought about by beginningless potencies of desire (_vasana_) associated with it. The preceding knowledge determines the succeeding one and that another and so on. Knowledge, pleasure, pain, etc. are not qualities requiring a permanent entity as soul in which they may inhere, but are the various forms in which knowledge appears. Even the cognition, "I perceive a blue thing," is but a form of knowledge, and this is often erroneously interpreted as referring to a permanent knower. Though the cognitions are all passing and momentary, yet so long as the series continues to be the same, as in the case of one person, say Devadatta, the phenomena of memory, recognition, etc. can happen in the succeeding moments, for these are evidently illusory cognitions, so far as they refer to the permanence of the objects believed to have been perceived before, for things or knowledge-moments, whatever they may be, are destroyed the next moment after their birth. There is no permanent entity as perceiver or knower, but the knowledge-moments are at once the knowledge, the knower and the known. This thoroughgoing idealism brushes off all references to an objective field of experience, interprets the verdict of knowledge as involving a knower and the known as mere illusory appearance, and considers the flow of knowledge as a self-determining series in successive objective forms as the only truth. The Hindu schools of thought, Nyaya, Sa@mkhya, and the Mima@msa, accept the duality of soul and matter, and attempt to explain the relation between the two. With the Hindu writers it was not the practical utility of knowledge that was the only important thing, but the nature of knowledge and the manner in which it came into being were also enquired after and considered important.
Prama@na is defined by Nyaya as the collocation of instruments by which unerring and indubitable knowledge comes into being. The collocation of instruments which brings about definite knowledge consists partly of consciousness (_bodha_) and partly of material factors (_bodhabodhasvabhava_). Thus in perception the proper contact of the visual sense with the object (e.g. jug) first brings about a non-intelligent, non-apprehensible indeterminate consciousness (nirvikalpa) as the jugness (gha@tatva) and this later on combining with the remaining other collocations of sense-contact etc. produces the determinate consciousness: this is a jug. The existence of this indeterminate state of consciousness as a factor in bringing about the determinate consciousness, cannot of course be perceived, but its existence can be inferred from the fact that if the perceiver were not already in possession of the qualifying factor (_vis'e@sanajnana_ as jugness) he could not have comprehended the qualified object (_vis'i@s@tabuddhi_} the jug (i.e. the object which possesses jugness). In inference (_anuma@na_) knowledge of the li@nga takes part, and in upamana the sight of similarity with other material conglomerations. In the case of the Buddhists knowledge itself was regarded as prama@na; even by those who admitted the existence of the objective world, right knowledge was called prama@na, because it was of the same form as the external objects it represented, and it was by the form of the knowledge (e.g. blue) that we could apprehend that the external object was also blue. Knowledge does not determine the external world but simply enforces our convictions about the external world. So far as knowledge leads us to form our convictions of the external world it is prama@na, and so far as it determines our attitude towards the external world it is prama@naphala. The question how knowledge is generated had little importance with them, but how with knowledge we could form convictions of the external world was the most important thing. Knowledge was called prama@na, because it was the means by which we could form convictions (_adhyavasaya_) about the external world. Nyaya sought to answer the question how knowledge was generated in us, but could not understand that knowledge was not a mere phenomenon like any other objective phenomenon, but thought that though as a gu@na (quality) it was external like other gu@nas, yet it was associated with our self as a result of collocations like any other happening in the material world. Prama@na does not necessarily bring to us new knowledge (_anadhigatadhi-gant@r_) as the Buddhists demanded, but whensoever there were collocations of prama@na, knowledge was produced, no matter whether the object was previously unknown or known. Even the knowledge of known things may be repeated if there be suitable collocations. Knowledge like any other physical effect is produced whenever the cause of it namely the prama@na collocation is present. Categories which are merely mental such as class (_samanya_), inherence (_samavaya_), etc., were considered as having as much independent existence as the atoms of the four elements. The phenomenon of the rise of knowledge in the soul was thus conceived to be as much a phenomenon as the turning of the colour of the jug by fire from black to red. The element of indeterminate consciousness was believed to be combining with the sense contact, the object, etc. to produce the determinate consciousness. There was no other subtler form of movement than the molecular. Such a movement brought about by a certain collocation of things ended in a certain result (_phala_). Jnana (knowledge) was thus the result of certain united collocations (_samagri_) and their movements (e.g. contact of manas with soul, of manas with the senses, of the senses with the object, etc.). This confusion renders it impossible to understand the real philosophical distinction between knowledge and an external event of the objective world. Nyaya thus fails to explain the cause of the origin of knowledge, and its true relations with the objective world. Pleasure, pain, willing, etc. were regarded as qualities which belonged to the soul, and the soul itself was regarded as a qualitiless entity which could not be apprehended directly but was inferred as that in which the qualities of jnana, sukha (pleasure), etc. inhered. Qualities had independent existence as much as substances, but when any new substances were produced, the qualities rushed forward and inhered in them. It is very probable that in Nyaya the cultivation of the art of inference was originally pre-eminent and metaphysics was deduced later by an application of the inferential method which gave the introspective method but little scope for its application, so that inference came in to explain even perception (e.g. this is a jug since it has jugness) and the testimony of personal psychological experience was taken only as a supplement to corroborate the results arrived at by inference and was not used to criticize it [Footnote ref 555].
Sa@mkhya understood the difference between knowledge and material events. But so far as knowledge consisted in being the copy of external things, it could not be absolutely different from the objects themselves; it was even then an invisible translucent sort of thing, devoid of weight and grossness such as the external objects possessed. But the fact that it copies those gross objects makes it evident that knowledge had essentially the same substances though in a subtler form as that of which the objects were made. But though the matter of knowledge, which assumed the form of the objects with which it came in touch, was probably thus a subtler combination of the same elementary substances of which matter was made up, yet there was in it another element, viz. intelligence, which at once distinguished it as utterly different from material combinations. This element of intelligence is indeed different from the substances or content of the knowledge itself, for the element of intelligence is like a stationary light, "the self," which illuminates the crowding, bustling knowledge which is incessantly changing its form in accordance with the objects with which it comes in touch. This light of intelligence is the same that finds its manifestation in consciousness as the "I," the changeless entity amidst all the fluctuations of the changeful procession of knowledge. How this element of light which is foreign to the substance of knowledgerelates itself to knowledge, and how knowledge itself takes it up into itself and appears as conscious, is the most difficult point of the Sa@mkhya epistemology and metaphysics. The substance of knowledge copies the external world, and this copy-shape of knowledge is again intelligized by the pure intelligence (_puru@sa_) when it appears as conscious. The forming of the buddhi-shape of knowledge is thus the prama@na (instrument and process of knowledge) and the validity or invalidity of any of these shapes is criticized by the later shapes of knowledge and not by the external objects (_svata@h-prama@nya_ and _svata@h-aprama@nya_). The prama@na however can lead to a prama or right knowledge only when it is intelligized by the puru@sa. The puru@sa comes in touch with buddhi not by the ordinary means of physical contact but by what may be called an inexplicable transcendental contact. It is the transcendental influence of puru@sa that sets in motion the original prak@rti in Sa@mkhya metaphysics, and it is the same transcendent touch (call it yogyata according to Vacaspati or samyoga according to Bhik@su) of the transcendent entity of puru@sa that transforms the non-intelligent states of buddhi into consciousness. The Vijnanavadin Buddhist did not make any distinction between the pure consciousness and its forms (_akara_) and did not therefore agree that the akara of knowledge was due to its copying the objects. Sa@mkhya was however a realist who admitted the external world and regarded the forms as all due to copying, all stamped as such upon a translucent substance (_sattva_) which could assume the shape of the objects. But Sa@mkhya was also transcendentalist in this, that it did not think like Nyaya that the akara of knowledge was all that knowledge had to show; it held that there was a transcendent element which shone forth in knowledge and made it conscious. With Nyaya there was no distinction between the shaped buddhi and the intelligence, and that being so consciousness was almost like a physical event. With Sa@mkhya however so far as the content and the shape manifested in consciousness were concerned it was indeed a physical event, but so far as the pure intelligizing element of consciousness was concerned it was a wholly transcendent affair beyond the scope and province of physics. The rise of consciousness was thus at once both transcendent and physical.
The Mima@msist Prabhakara agreed with Nyaya in general as regards the way in which the objective world and sense contact induced knowledge in us. But it regarded knowledge as a unique phenomenon which at once revealed itself, the knower and the known. We are not concerned with physical collocations, for whatever these may be it is knowledge which reveals things--the direct apprehension that should be called the prama@na. Prama@na in this sense is the same as pramiti or prama, the phenomenon of apprehension. Prama@na may also indeed mean the collocations so far as they induce the prama. For prama or right knowledge is never produced, it always exists, but it manifests itself differently under different circumstances. The validity of knowledge means the conviction or the specific attitude that is generated in us with reference to the objective world. This validity is manifested with the rise of knowledge, and it does not await the verdict of any later experience in the objective field (_sa@mvadin_). Knowledge as nirvikalpa (indeterminate) means the whole knowledge of the object and not merely a non-sensible hypothetical indeterminate class-notion as Nyaya holds. The savikalpa (determinate) knowledge only re-establishes the knowledge thus formed by relating it with other objects as represented by memory [Footnote ref 556].
Prabhakara rejected the Sa@mkhya conception of a dual element in consciousness as involving a transcendent intelligence (_cit_) and a material part, the buddhi; but it regarded consciousness as an unique thing which by itself in one flash represented both the knower and the known. The validity of knowledge did not depend upon its faithfulness in reproducing or indicating (_pradars'akatva_) external objects, but upon the force that all direct apprehension (_anubhuti_) has of prompting us to action in the external world; knowledge is thus a complete and independent unit in all its self-revealing aspects. But what the knowledge was in itself apart from its self-revealing character Prabhakara did not enquire.
Kumarila declared that jnana (knowledge) was a movement brought about by the activity of the self which resulted in producing consciousness (_jnatata_) of objective things. Jnana itself cannot be perceived, but can only be inferred as the movement necessary for producing the jnatata or consciousness of things. Movement with Kumarila was not a mere atomic vibration, but was a non-sensuous transcendent operation of which vibrationwas sometimes the result. Jnana was a movement and not the result of causal operation as Nyaya supposed. Nyaya would not also admit any movement on the part of the self, but it would hold that when the self is possessed of certain qualities, such as desire, etc., it becomes an instrument for the accomplishment of a physical movement. Kumarila accords the same self-validity to knowledge that Prabhakara gives. Later knowledge by experience is not endowed with any special quality which should decide as to the validity of the knowledge of the previous movement. For what is called sa@mvadi or later testimony of experience is but later knowledge and nothing more [Footnote ref 557]. The self is not revealed in the knowledge of external objects, but we can know it by a mental perception of self-consciousness. It is the movement of this self in presence of certain collocating circumstances leading to cognition of things that is called jnana [Footnote ref 558]. Here Kumarila distinguishes knowledge as movement from knowledge as objective consciousness. Knowledge as movement was beyond sense perception and could only be inferred.
The idealistic tendency of Vijnanavada Buddhism, Sa@mkhya, and Mima@msa was manifest in its attempt at establishing the unique character of knowledge as being that with which alone we are in touch. But Vijnanavada denied the external world, and thereby did violence to the testimony of knowledge. Sa@mkhya admitted the external world but created a gulf between the content of knowledge and pure intelligence; Prabhakara ignored this difference, and was satisfied with the introspective assertion that knowledge was such a unique thing that it revealed with itself, the knower and the known, Kumarila however admitted a transcendent element of movement as being the cause of our objective consciousness, but regarded this as being separate from self. But the question remained unsolved as to why, in spite of the unique character of knowledge, knowledge could relate itself to the world of objects, how far the world of external objects or of knowledge could be regarded as absolutely true. Hitherto judgments were only relative, either referring to one's being prompted to the objective world, to the faithfulness of the representation of objects, the suitability of fulfilling our requirements, or to verification by lateruncontradicted experience. But no enquiry was made whether any absolute judgments about the ultimate truth of knowledge and matter could be made at all. That which appeared was regarded as the real. But the question was not asked, whether there was anything which could be regarded as absolute truth, the basis of all appearance, and the unchangeable, reality. This philosophical enquiry had the most wonderful charm for the Hindu mind.