Yoga Sutra - Samādhi Pada 1.7
प्रत्यक्षानुमानागमाः प्रमाणानि ॥७॥
pratyakṣa-anumāna-āgamāḥ pramāṇāni ||7||
Valid cognitions are perception, inference, and valid testimony.
Right knowledge consists of sense perception, logic, and verbal testimony.
The first of the five vṛttis to be discussed is pramāṇa, the central concern of epistemology, that is, what sources constitute valid knowledge of an object, the methods of attaining accurate information about reality. Philosophy and, of course, science—Sāṅkhya, after all, sees itself as dealing with physical verifiable truths—have as their goals the attainment of knowledge about reality, so it is standard in Indic philosophical discourse for scholastics to state which methods of attaining such knowledge of reality they accept as valid. The Yoga school accepts three sources of receiving knowledge, as does the Sāṅkhya tradition (Sāṅkhya Kārikā IV), but other philosophical schools accept differing numbers from one to six.
The first method of attaining valid knowledge listed by Patañjali is sense perception: We can know something to be true or valid if we experience it through one or more of our senses—if we see, smell, touch, hear, or taste it. So, for example, you “know” this book is real because you see it and feel it. Śaṅkara notes that sense perception, empiricism, is placed first on the list of pramāṇas because the other pramāṇas are dependent on it.
Vyāsa defines sense perception as the state or condition of the mind, vṛtti, that apprehends both the specific (viśeṣa) and generic (sāmānya) nature of an external object through the channels of the five senses. The generic and specific nature of objects are categories especially associated with the Vaiśeṣika school of Hindu philosophy and are technical ways of attempting to analyze physical reality. The generic nature of a dog that one might happen to come upon, for example, is that it belongs to the canine species, the specific nature is that which demarcates it from other members of this generic category, that it is, let us say, a ginger Irish terrier. (Technically speaking, viśeṣa is what differentiates ultimate irreducible entities such as the smallest subatomic particles of matter from each other, but Vyāsa is using the term in a more general sense, since dogs, as all material objects, are made up of conglomerates of atoms. When one sees a particular dog, the mind typically apprehends both its generic and specific natures. This is accomplished by the citta encountering a sense object through the senses and forming an impression of this object, a vṛtti. More specifically, the tāmasic natures of sense objects imprint themselves upon the mind and are then illuminated in the mind by the mind’s sāttvic nature. Due to pervading the mind, the puruṣa’s awareness then becomes conscious of this mental impression, as if it were taking place within itself, indistinguishable from itself. In actual fact, the impression is imprinted on the citta, mind, which is pervaded by consciousness.
Vācaspati Miśra raises a question here. If the impression is imprinted on the mind, which, according to the metaphysics of Yoga, is a totally separate entity from the puruṣa soul, then how is it that the latter is aware of it? Or, as he puts it, if an axe cuts a khadira tree, it is not a plakṣa tree that is thereby cut. In other words, if an impression is something that is made on the mind, then how does it end up being made on the puruṣa? Here, again, Vācaspati Miśra introduces the analogy of the mirror. It is the mind and intelligence, not the soul, that take the form of the object as a result of sense perception. According to the reflection model of awareness, consciousness is reflected in the intelligence due to their proximity and then is misidentified with the reflection by the mind.
This reflection, in turn, is altered according to the form assumed by the intelligence—just as a reflection appears dirty if the mirror is dirty. Thus, since the mind and intelligence have taken the form of the object in question, consciousness sees its own reflection as containing that form. This corresponds to the analogy of the moon appearing rippled when reflected in rippling water. According to the nonreflection model, awareness simply pervades the citta just as it pervades the body and is misidentified as being nondifferent from the forms of citta in the same way as it is misidentified with the form of the body. According to either manner of conceptualization, this misidentification of the awareness of puruṣa with the forms of the intellect is the essence of ignorance.
Moving on to the second pramāṇa, source of receiving valid knowledge, mentioned by Patañjali in this sūtra, Vyãsa defines anumāna, inference, as the assumption that an object of a particular category shares the same qualities as other objects in the same category, qualities that are not shared by objects in different categories. He gives the rather clumsy example of the moon and stars, which belong to the category of moving objects because they are seen to move, but mountains belong to a category of immobile objects, because they have never been seen to move. Thus, if one sees an unfamiliar mountain or hill, one can infer that it will not move, because other known objects in this category, all mountains and hills with which one is familiar, do not move.
The more classical example of inference among Hindu logicians is that fire can be inferred from the presence of smoke. Since wherever there is smoke, there is invariably fire causing it, the presence of fire can be inferred upon the perception of smoke even if the actual fire itself is not perceived. So if one sees clouds of smoke billowing forth from a distant mountain, one can say with certainty that there must be fire on it, even if one cannot actually see the blaze itself. It is in this regard that inference, anumāna, differs from the first source of knowledge, pratyakṣa, sense perception. Pratyakṣa requires that one actually see the fire. In anumāna, the fire itself is not actually seen, but its presence is inferred from something else that is perceived, smoke. The principle here is that there must always be an absolute and invariable relationship (vyāpti, concomitance) between the thing inferred, say, the fire, and the reason on which the inference is made, the presence of smoke—in other words, wherever there is or has ever been smoke there must at all places and at all times always be or have been fire present as its cause with no exceptions. If these conditions are met, the inference is accepted as a valid source of knowledge. If exceptions to the rule can be found, even one instance of smoke ever that does or did not have fire as its cause, then the inference is invalid.
Finally, āgama, verbal testimony, the third source of valid knowledge accepted by Patañjali, is the relaying of accurate information through the medium of words by a trustworthy person who has perceived or inferred the existence of an object, to someone who has not. Vyāsa describes a trustworthy person as someone whose statements cannot be contradicted. Vācaspati Miśra adds that such a person should have keen sense organs and be trustworthy and compassionate, and Vijñānabhikṣu, that a reliable or trustworthy person is one who is free from defects such as illusion, laziness, deceit, dull-wittedness, and so forth. The words of such a reliable authority enter the ear and produce an image, vṛtti, in the mind of the hearer that corresponds to the vṛtti experienced by the trustworthy person. The person receiving the information in this manner has neither personally experienced nor inferred the existence of the object of knowledge, but valid knowledge of the object is nonetheless achieved, which distinguishes this source of knowledge from the two discussed previously.
The most important category of valid knowledge in the form of āgama, verbal testimony, is divine scripture, which is also referred to as śruti, that which is heard, or śabda, the word. Since scriptures are considered to have been uttered by trustworthy persons in the form of enlightened sages and divine beings, their status as trustworthy sources of knowledge is especially valuable. In order to elaborate on this, Vācaspati Miśra raises the issue of how sacred scriptures can be considered valid given that all accurate verbal knowledge must itself originally come either from perception or inference (hence the Cārvāka and Vaiśeṣika schools do not even consider them separate sources of knowledge), but scriptures deal with certain subjects that no human being has either seen or inferred (such as the existence of heavenly realms). Vācaspati Miśra responds that the truths of scripture have been perceived by God, Īśvara; thus divine scripture, too, is based on perception—and God, quips Rāmānanda Sarasvatī, is surely a trustworthy person! However, Vācaspati Miśra, in his commentary to the Saṅkhya Kārikā (V), precludes the blind acceptance of scripture by qualifying that revelation may be a useful means of attaining knowledge only if it has a solid foundation, contains no internal contradictions, is supported by reason, and is accepted by people in general.
Vyāsa makes a telling comment in I.32 relevant to the hierarchy of Yoga epistemology. Perception is superior to any other sources of knowledge—indeed, the other sources of knowledge are based on it. If we consider the syllogism there is fire on the mountain because there is smoke, even though the fire is not seen by direct perception and therefore an inference is required to establish its existence, this inference is dependent on perception insofar as the sign (liṅga) of the fire, namely, smoke, is perceived. So valid inferences are also dependent on perception. And, as indicated, verbal authority is predicated on the original perception of the object of information by the relayer of the information. Additionally, it can be argued that accepting knowledge from a verbal authority is nothing other than making an inference—one makes an inference that a verbal authority is reliable and does not counter perceivable data. Verbal authority too, then, is indirectly derived from direct perception. Therefore some schools of thought, like that associated with the materialist Cārvāka, accept the need for only one pramāṇa, that of sense perception. The Yoga school accepts three sources but is very clear that it considers pratyakṣa the highest, not just because the other pramāṇas depend on it, but (as will become clearer in I.49) because it is the only way of truly knowing the essential nature of an object.
Different schools of thought prioritized different pramāṇas. The Nyāya school features anumāna, dedicating itself for centuries to refining categories of logic, and Sāṅkhya, too, was associated with this epistemology.70 The Vedānta school occupied itself with āgama (Vedānta Sūtras I.1.3), dedicating itself to the interpretation and systematization of the Upaniṣads and the Vedānta Sūtras derived from them; the Mīmāṁsā school, too, prioritized āgama and became especially associated with developing hermeneutics, the methods of scriptural interpretation.71 While Patañjali accepts āgama as a valid source of knowledge, he does not quote or even indirectly refer to a single verse from scripture in his treatise (in contrast with the Vedānta Sūtras, which are almost entirely composed of references from the Upaniṣads). The very fact that he categorizes āgama as a vṛtti and thus comparable in one sense with other vṛttis such as viparyaya, error, the subject of the next sūtra, points to correspondences with aspects of post-Enlightenment thought, namely, that verifiable in this case yogic) experience trumps scripture. This has been termed a “radical mystico-yogic orientation,” since, certainly, as with the Enlightenment, such claims would have challenged the mainstream Vedic authority of the day. As for anumāna, while Patañjali uses this source of knowledge on occasion, such as in his arguments against certain Buddhist views, (IV.14–24), clearly almost his entire thrust throughout the sūtras is on pratyakṣa as the ultimate form of knowledge. Anumāna and āgama are forms of knowledge, but mediate forms, the truths of which are indirect, where the Yoga tradition bases its claims to authoritativeness on direct, personal experience.
It is because of this orientation that yoga is, in my view, destined to remain a perennial source of interest to the empirical dispositions of the modern world. One must also note that there are different types of pratyakṣa: the commentary on the Sāṅkhya Kārikā, the Yukti-dīpikā, speaks of yogic perception as well as sensual perception (38.2). Indeed, several schools make a distinction between apara–pratyakṣa, conventional perception, and para-pratyakṣa, supernormal perception, or, as the Sāṅkhya Sūtras put it, external perception, bāhya-pratyakṣa, and internal perception abāhya-pratyakṣa (I.90).73 As will become clearer later in the text, the perception of interest to Yoga is the latter, that of a supernormal nature. But even the startling claims of omniscience that occur later in the text are relevant only as signposts of experiences that the yogī will encounter on the path of Yoga, not as articles of faith.