These fluctuations are correct knowledge, misconception, imagination, deep sleep, and memory.

A Complete Inventory of Mental Activity

Having flagged the kliṣṭa and akliṣṭa quality of mental fluctuations, Patañjali now names the five functional categories themselves: pramāṇa, valid cognition; viparyaya, mistaken cognition; vikalpa, verbally constructed concepts without a real referent; nidrā, the fluctuation of deep sleep; and smṛti, memory. Vijñānabhikṣu treats this list as exhaustive rather than illustrative, meaning that whatever content shows up in a meditator's awareness, from a sharp insight to a drifting daydream, belongs to one of these five and to no sixth category.

The Function Each Category Performs

Pramāṇa gives accurate contact with an object through perception, inference, or testimony, as the following sutra spells out. Viparyaya is a confident but false reading of a real object, the rope mistaken for a snake. Vikalpa is a concept generated purely by language, with no object behind it at all, such as an abstract fear built entirely from words. Nidrā is unusual among the five because its content is the absence of objects rather than any positive object, yet it is still classed as an active modification since the sleeper can later report having experienced it. Smṛti is the retrieval of a previously experienced object back into present awareness through the saṃskāra it left behind.

Why the Order and Completeness Matter for Practice

The placement of this sutra early in the chapter is strategic: the technical vocabulary Patañjali uses later for describing samādhi, obstacles, and the refinement of attention assumes the reader can already sort raw mental content into these five bins without confusion. A student who cannot tell viparyaya from vikalpa, for instance, will struggle later to distinguish a genuine insight from an elaborate but empty conceptual construction mistaken for realization. Because the scheme covers ordinary waking activity as much as formal sitting, a person practicing this discrimination while working, speaking, or resting is applying the sutra just as much as one doing so on a meditation cushion, since none of the five functions is confined to seated practice.

Naming the Function Before the Content

This practice builds the habit of identifying which of the five functions is active, independent of whatever the thought happens to be about.

The Naming Sit

1. Sit for ten minutes and let the mind move as it will.
2. When a thought surfaces, silently name its category: knowledge, error, concept, sleepiness, or memory.
3. Resist the urge to analyze the content itself; only the category matters here.
4. If you notice you drifted into a story, name that drift as memory or concept and return to naming.
5. At the end, note which category appeared most often in this particular sitting.

Tracking Chains Across a Sitting

6. During a longer sit, notice when one category triggers the next, such as memory leading into concept.
7. Write down one such chain afterward, naming each link in order.
8. Identify which link you could have interrupted with steadier attention.
9. Compare chains from different days to see which category most often opens the sequence.

Assuming the Scheme Applies Only to Formal Meditation

Some readers treat this fivefold list as relevant only to seated practice, but Vyāsa applies it to the whole of waking life, including conversation, driving, and work. A judgment made mid-conversation, a recollection during a meeting, and a drowsy lapse in the afternoon each fall under one of these five headings just as much as anything noticed on a cushion. Confining the scheme to formal sitting misses the sutra's intent to cover the entirety of mental function.

Ranking the Five as Better or Worse

A further misreading treats pramāṇa as inherently superior and the other four as failures to be eliminated. The list is functional, not a moral ladder; even valid cognition is still a fluctuation that must eventually quiet in deeper absorption, so accumulating correct knowledge is not itself the finish line the sutra points toward.