Another thing that the Yoga-sutras have borrowed from Buddhism is the notion of bhumi (land) in the sense of level or state of the mind in its advance towards kaivalya. These bhumis are: ksipta (restless), mudha (torpid), viksipta (distracted), ekagra (one-pointed), and niruddha (suppressed). The first two involve the predominance of rajas and tamas respectively; in the third sattva is predominant with some rajas. The fourth is the predominance of sattva. The fifth is the arrest of all gunas, but persistence of samskaras in the 'unconscious'. (Very much what Vipassana teaches.)
I was thinking: this is what we need to stress in our novitiate and post-novitiate. Obviously all our candidates, and all of us too, are restless, torpid, distracted, and we have to become one-pointed. But even at this fourth stage there is the work of handling the subconscious. Only beyond this is kaivalya or whatever it is that is homologous to kaivalya....
Hence the practice of sitting... under guidance.
"[T]he Yoga of Patanjali may at its best approach 'natural mysticism'" (Guidelines 256) A judgment shared also by Bede Griffiths.