pratyakṣa – direct (sense) perception; anumāna – inference, logic; agamāḥ – scriptural testimony, authoritative texts, words of authoritative teachers, Rishis, & guru; pramāṇāni – (are the) sources of comprehension, correct understanding:
The sources of correct understanding are direct perception, inference and the words (written or spoken) of authorities.
All the English synonyms for each of the Sanskrit words in this śloka are relatively easy to follow. I just want to make mention of agamāḥ, which is authoritative testimony. In the ancient Vedic culture, since the very beginnings, these were considered a scriptural authority, or written spiritual texts; words of the great saintly teachers or the rishis, and genuine or bona fide gurus.
Agamāḥ, or ‘an authority’ in the common sense, would be applied for instance, to a professor in a university. If I want to study some subject and I approach somebody that has that knowledge already, then they can impart that to me, and I can derive a correct understanding on that particular subject. It should be understood, however, that the authoritative speaker does not ‘create’ agamāḥ; rather, whatever is being presented is considered agamāḥ if it is actual truth, and therefore the person speaking it can be also considered an authority. If a teacher is wrong in what they are saying or presenting, then that is not agamāḥ. It is not just a blind acceptance of authority based upon external consideration; it’s based upon the ability to speak and to pass on that which is truth, in the Vedic teachings. So, agamāḥ or testimony is presented as a higher principle.
This first of the five vṛttis mentioned by Patañjali, is called pramāṇāni, or the different methods of obtaining accurate information about reality. How one perceives and correctly understands reality is dealt with in great detail in the sāṇkhya -yoga system. The originator of sāṇkhya-yoga was the great Kapiladeva. Historically there were two Kapilas. There was an incarnation of Lord Vishnu, who spoke the original sāṇkhya philosophy to his mother Devahūti. Then a considerable time after that, though still in ancient times for us, there was another proponent of sāṇkhya also bearing the name Kapila, who codified many of these teachings in a sāṅkhya text but did not present everything the original Kapila taught. And sometimes there is a bit of confusion between these two personalities.
Vyāsa, the earliest known commentator that we have on Patañjali’s Yoga-sūtra, concludes his commentary by stating that this is the commentary of sāṇkhya-yoga, as is propounded by Patañjali. So, we understand that not all of the principles that were presented by the second Kapila, are completely in line with older Vedic authority and Vedic teachings. For that reason, we don’t necessarily accept all of Vyāsa’s commentary as being true to what Patañjali meant because his commentary does not always align with Vedic authority – agamāḥ.
The direct perception mentioned here is of course referencing the ordinary senses. But there has to be an understanding and appreciation regarding the limitations placed on the senses. It is true that our five senses can indicate to us some reality as opposed to a fantasy, but we also understand that there are limitations to this perception, especially regarding the ultimate spiritual reality. Our eyes are very limited, and one must be gifted with spiritual vision in order to truly see things as they are, which is what the quest for spiritual realization is all about.
So, while the direct perception of things gives us a sense of what is real or apparently of substance in this world, we understand there is a limitation, and the same also applies to the use of logic – here referred to as anumāna.
For instance, we can learn by the process of deductive logic how heat can burn, simply by observing someone else. If I see a young child or someone accidentally touching a flame on a candle and they burn their finger, then I can deduct that whenever I see this substance called fire emitting heat and light, that it is capable of burning. I can also extend that logic to anything that is emitting or giving off enough heat – that if I get too close to it, I can be burned. So, this is the use of deductive logic or anumāna. It does however have its limitations.
Our senses are limited, and therefore cannot prove that there is no reality beyond the limits of our perception. For example, I may only see a distance of just five miles or five kilometers, and then everything is gone from my vision. If an object is situated beyond the limits of what I can see, it doesn’t mean that it doesn’t exist; it just means that I have limited sensual perception.
Vedic pramāṇa is different in that distinguishes between logic and testimonial authority. The word śabda literally means sound, but the śabda that is cited as authoritative Vedic testimony is known by the term śabda-brahman or spiritual sound, which is considered the ultimate authority, so it is in a category by itself, distinct from logic or anumāna, and pratyakṣa or direct perception. Spiritual sound, as opposed to ordinary sound, is also known as svataḥ-pramāṇa. And that means its authority is self-evident; it does not derive its authority from another pramāṇa.