Yoga Sutra 4.21 further and yet further ideas will be required.

Sūtra IV.21

If it is to be seen by another idea, further and yet further ideas will be required. And there will be confusion of memories

If it is to be seen by another idea, further and yet further ideas will be required. And there will be confusion of memories. If the idea the earlier idea which has perished of itself is to be seen by another idea which has arisen immediately afterwards in the stream of instants, then by whom is that idea of the idea known? The idea which knows the jar is here called the ‘idea’, and the idea for which it is itself an object is the ‘idea of the idea’. By whom is that idea of the idea known, if there is no abiding knower? It would have to be known by another, and that too by yet another, endlessly.

And if the ideas of the ideas are not known, then the affairs of the world will collapse, because the saṃskāra-s of memory will not be available. There will be an exponentially proliferating string of ideas of the idea of the jar, all on the same level, but not the idea of the jar itself. As there is no end to the ideas of the idea of the jar, how would the idea of an object like a jar ever be definite?

There is this further difficulty: And there will be confusion of memories. The ideas of the idea, and their saṃskāra-s, will have the same form, so that one would get a confusion of memories.

As many as were the experiences of the ideas of the idea, so many would be the consequent confused mass of memories. As a result of that confusion of the memories, memory would not be specific, in the form ‘this memory is of that idea’. In the uncertainty, how could we carry on our lives? From the similarity of the forms, confusion of memories would result.

However much we might know of ideas of an idea, since there could be no memory of an idea of the self and its previous activity, we should all meet each other in bewilderment. If, to escape the infinite regress, we should stop at a separate idea somewhere, then that itself would be the witness of the ideas. And thus, though He (Puruṣa the witness) is so obvious, from the indication that the ideas are witnessed, Everything – the whole world – is reduced to chaos by the Vaināśika Buddhists who explain away Puruṣa, who is the witness of the ideas.

(Opponent) We get out of the difficulty of an infinite regress with our assumption of seed-bed consciousness (ālaya-vijñāna), which avoids the supposition of self (ātman).

(Answer) If they suppose the nature of an experiencer anywhere at all, they are going against (their own) logic. That seed-bed (ālaya) consciousness too is something to be known, and so there is an infinite regress; it involves the same difficulties already mentioned.

Some particular Vaināsika Buddhists assume simple being of the nature of an experiencer, but calling it instead ‘simple being’ (sattva-mātra), which having cast off thrown off this set of five skandha-groups, namely matter, feeling, perception, mental construction, vijñāna-consciousness assembles holds together other skandha-groups. After saying which, they shrink back from (declaring openly) that very thing, the assumption of a single being which is the fashioner of the past and future skandha-groups.

And yet they have another view which contradicts themselves. They still say: ‘I will follow the life of brahmacarya under a teacher so that there may be revulsion from the skandha-groups, freedom from passion, that they may not arise but be at peace’ and then they go on to deny the existence of that very being which they have just accepted. Calling it Vijñāna-consciousness-only, momentary, or Void, they deny self (ātman).

The Sāṅkhya-s and Yoga-s and their followers (however) proclaim that by the word ‘self’ (sva) they understand Puruṣa alone, the Lord of the mind, the experiencer.

In what way do they understand the experiencer by the word ‘self (sva)? In this way: