Pregnant with the holy meaning, "At other times, the seer identifies with the fluctuating consciousness", Vrtti sarupyam itaratra stand as the fourth yoga sutra, which is contained in Patanjali Yoga Sutras.

Vrtti behaviour, fluctuation, modification, function, state of mind
sarupyam identification, likeness, closeness, nearness
itaratra at other times, elsewhere

At other times, the seer identifies with the fluctuating consciousness.

When the seer identifies with consciousness or with the objects seen, he unifies with them and disregards his splendour.

The natural disposition of consciousness is to become involved with the object seen, absorb the seer towards it, and move the seer to identify with it. Then the seer turns immersed into the object. This becomes the seed for diversification of the intelligence, and makes the seer forget his own healthy awareness.

When the soul does not emit its own glory, it is an indication that the thinking ability has manifested itself in place of the soul.

The imprint of objects is transmitted to citta through the senses of perception. Citta assimilates these sensory impressions and turns coloured and modified by them. Objects act as provisions for the grazing citta, which is drawn to them by its appetite. Citta designs itself, assuming the form of the objects in order to possess them. Thus it becomes enwrapped by thoughts of the object, with the result that the soul is clouded. In this manner, citta becomes turbid and induces alterations in behaviour and mood, because it distinguishes itself with things seen.

Although in reality citta is a formless entity, it can be useful to visualise it in order to comprehend its functions and limitations. One can envisage it to be similar to optical lens, containing no light of its own, but placed immediately above a source of pure light, the soul. One side of the lens, facing inwards towards light, stays clean.

In daily life, however, people are very much conscious of the upper surface of the lens, facing outwards to the world and connected to it by the senses and mind. This surface acts both as a sense, and as a content of consciousness, together with ego and intelligence. Worked upon by the desires and fears of tumultuous materialistic life, it becomes murky, opaque, even dirty and scarred, and keeps the soul`s light from shining through it. Deficient in inner illumination, it searches all the more passionately the artificial lights of conditioned existence. The whole procedure of yoga, its practice and control, is directed at disjointing consciousness from its identification with the phenomenal world, at controlling the senses by which it is entrapped, and at purging and purifying the lens of citta, until it beams entirely and only the light of the soul.