Correct knowledge arises from direct perception, logical inference, and authoritative testimony.

Three Routes to Reliable Cognition

This sutra unpacks pramāṇa, the first item of the previous list, into three recognized means: pratyakṣa, direct perception through the senses; anumāna, inference that extends beyond present sense contact through reasoning; and āgama, testimony from a source considered reliable. Vyāsa treats pratyakṣa as more than raw sensory contact, since it already involves the mind's determinate grasp of what the senses register, sorting sensation into a recognizable object.

How the Three Support and Check One Another

Anumāna reaches conclusions the senses alone cannot, as when steady behaviour across years is taken as evidence of an established inner discipline. Āgama is granted special standing in this system for matters that lie beyond both direct observation and ordinary inference, such as descriptions of puruṣa, but Śaṅkara's Vivaraṇa insists that testimony earns trust only from a speaker free of the motive to deceive, free of ignorance, and free of defective perception. A scripture or teacher is not automatically pramāṇa merely by claiming authority; the claim itself is subject to scrutiny using the same standard the sutra sets for any reliable source. In practice these three checks operate together rather than as competitors, since a claim from testimony can be tested where possible against inference, and a conclusion from inference can be tested where possible against direct observation.

Relevance to the Path That Follows

Because the entire structure of classical yoga rests on discriminating pramāṇa from its four counterparts, this sutra functions as an epistemological foundation for everything that follows. A practitioner uses āgama to learn the outline of the path from the Sutras themselves, anumāna to apply that outline sensibly to a particular life and body, and pratyakṣa to confirm through direct experience that a given practice is actually producing the steadiness it claims to produce. Vyāsa's broader point is that yoga is meant to be verifiable rather than merely asserted, and this threefold account of valid knowledge is what makes that verification possible instead of leaving the practitioner to rely on unexamined belief.

Testing a Belief Against All Three Sources

Applying the threefold test to a specific claim about one's own practice sharpens the difference between assumption and verified knowledge.

The Three-Source Check

1. State a belief about your practice plainly, such as noticing calmer sleep since starting to meditate.
2. Check pratyakṣa: can you point to a directly observed change across recent nights?
3. Check anumāna: does it follow reasonably from what is already known about steady practice and rest?
4. Check āgama: does a reliable teacher or text corroborate this kind of outcome?
5. If it passes some but not all three, hold the belief as provisional rather than settled.

Testing a Received Instruction

6. Take an instruction you were given, such as a particular breathing ratio.
7. Ask whether you have personally verified it through pratyakṣa across several sessions.
8. Ask whether it holds up under anumāna given what you already understand about breath and effort.
9. Ask whether it traces to a reliable āgama source rather than an unverified secondhand claim.

Treating Āgama as Automatic Authority

A frequent error is assuming any statement from an old text or a teacher qualifies as āgama simply by virtue of its source. Śaṅkara's standard requires the source to be free of deceptive motive, ignorance, and defective perception, so age or tradition alone does not confer reliability; the claim itself remains open to the same scrutiny applied to any other source.

Weighting the Three Sources Equally in Every Case

A subtler mistake treats pratyakṣa, anumāna, and āgama as always carrying equal force regardless of subject. Physical, observable claims lean naturally on perception and inference, while claims about puruṣa or the deeper mechanics of samādhi necessarily rely more heavily on āgama for a practitioner who has not yet verified them directly. Flattening this distinction leads either to dismissing tradition outright or to demanding sensory proof for matters ordinary observation cannot yet settle.