Letters of Sri Aurobindo
Fragment ID: 8673
(this fragment is largest or earliest found passage)
Sri Aurobindo — Unknown addressee
Tibetan Yoga 
Evans-Wentz writes: “There is... according to Mahāyānic Buddhism... unending evolutionary progression; so that Nirvāṇa is to be regarded as a Spiritual Rest-House on the Highway through Eternity” [p. 149]. And also: “Man, then no longer man, will... help to fulfil the Law of the Higher Evolution, of which Nirvāṇa is but the beginning” [p. 12]. The above indicate that Nirvana is not the final aim – but whether this is a compromise with Vedanta or with modern ideas is very doubtful. There is almost a contradiction with the following:
“When the Ignorance which was to be overcome hath been dispersed, the effort to overcome it ceaseth, and the Path cometh to an end and the Journey is completed.
“The Journeying having ceased, there is no place beyond the ending of the Path to explore; and one obtaineth the Supreme Boon of the Great Symbol, the Unabiding State of Nirvāṇa.”1
The two statements [i.e. the two sentences from Evans-Wentz’s commentary and the two paragraphs from the Tibetan text] are not only almost but absolutely contradictory. Nirvana cannot be at once the ending of the Path with nothing beyond to explore and yet only a rest house or rather the beginning of the Higher Path with everything still to explore. I think that different views of different Buddhist minds or schools must have been jumbled together without reconciliation. The reconciliation would be that it is the end of the lower Path through the lower Nature and the beginning of the Higher Evolution. In that case it would accord exactly with the teaching of our Yoga.
1 These two paragraphs are from “The Epitome of the Great Symbol” as translated by Lama Kazi Dawa-Samdup and Evans-Wentz and published in Tibetan Yoga and Secret Doctrines, p. 149. – Ed.