Below is an excerpt from Henry Corbin's book, "Avicenna and the Visionary Recital." Translated by Willard R. Trask. Routledge & Kegan Paul: London. 1960. Pg. 27-28. The excerpt from a chapter called, "The Cosmic Crypt: The Stranger and the Guide."
"This soteriology, the encounter with the transcendent Self, which is at once the same and not the same as "myself," is, we have said, as it were in synchronism with the soul's awakening to its consciousness of being a Stranger. Works of philosophy, spiritual romances in prose, or mystical poems here furnish abundant documents for a phenomenology of the stranger-consciousness. In a philosophical treatise of Ismailian cast that is attributed to him, Nasiraddin Tusi makes a beginning toward this phenomenology, in striking figures. What is the meaning of "coming into this world" (being cast into the depths of the cosmic crypt)? It has not, in itself, the meaning of a change in corporeal position: to qualify the situation in cosmic space will be possible only after orientation in that space. "To come into this world" is to pass from the world of Reality in the true sense (haqiqat) to the world that is doubtless real for ordinary consciousness, but which in the true sense is only figure and metaphor (majaz); this coming into the world means that realities in the true sense have become doubtful or improbable, suspect and ambiguous. "To leave this world," to reach the true world, will mean that this Darkness and these doubts are removed from a consciousness that passes from the state of infancy (hal-e tifuliya) to the age of maturity. To attain this true consciousness of the True Real is eo ipso to become a stranger to the world of metaphor, with which ordinary consciousness remains satisfied as a true world. To leave this world is not to "die" as those have died of whom it is said that they have "departed," for many of those who have thus departed have in fact never left the world. Their departure too is metaphorical, for it is not thus that, in the true sense, one leaves the cosmic crypt. Really to leave it, one must have become, or rather have again become, the Stranger---that is, a soul regenerated in the Spring of Life, having accomplished the passage of return from Majaz to Haqiqat. It is this passage toward haqiqat, Reality in the true sense, that signifies exodus from this world, in the true sense."