Sri Aurobindo
Letters of Sri Aurobindo
Volume 1
I don’t think it is at all owing to the suggestion from what I wrote in the letter that you got the experience. The fundamental reason of these things does not belong to the surface; it is in the depths – or on the heights; at any rate, in the inner being behind the veil of the frontal consciousness. The actual occasional cause of the spiritual experience,– the match that sets alight the fire, so to say – may be something very slight and looking accidental on the surface, a chance word or happening or something quite fortuitous in its appearance. The person also through whom it comes may seem very much like a fortuitous instrument. It is true that this is only in appearance; for even things slight and seemingly fortuitous have a reason for happening as they do, but that reason too is not on the surface.
Your meeting with Subhash [Bose] was not on the physical plane, nor was it with the physical Subhash. Although it was not a sleep in which we enter into other planes of being, it was in a concentrated state in which you had crossed or were crossing the border from the physical to a deeper consciousness. The Subhash you met there was some part of him of which the external physical Subhash is probably not himself aware and there it is quite possible that there is a Shivabhakta who could speak in praise of Gauri-vallabh; it may be even from there that come the velleities of sadhana when he is in prison and the surface kinetic man discouraged and inactive. Or it may be the Subhash met in the concentration was only a mask or an instrument for a Power that spoke the word through his voice.
As for the experience itself it takes up the movement which had started in you a long time ago and was interrupted by 
the vital upheaval that brought you so much trouble and struggle. Only there has been since a widening of the consciousness and a step forward which made this form of the experience possible. At that time you had not much appreciation for calm and peace – you hankered only after bhakti and Ananda. But calm, peace, shanti are the necessary basis for any establishment of other things, otherwise if there is no solid foundation in the consciousness, if there is only unrest and movement, bhakti, Ananda and everything else can only come and go in starts and fits and find no ground to live on. It must, however, be not a mere mental quiet but the deep spiritual peace of the shantimaya Shiva. It was this that touched you (descending through the head) in this experience. For the rest it is a resumption of the piercing of the veil, the beginning of the power of inner experience as opposed to the lesser experiences of the surface, the opening of the inner being, which is necessary for the Yogic consciousness. A certain amount of vital purification has taken place which made the resumption of this kind of experience possible.
You certainly need not be afraid of going into unconsciousness, for it is not unconsciousness that you would go into, but simply the inner consciousness,– that going quite inward which is the result of intense dhyāna [meditation] and the beginning of a certain kind of samādhi.