We find a testimony of this sense of the voyage in the vast work of a seventeenth-century
Persian platonist, Mullah Sadra Shirazi. One of the greatest names in Iranian philosophy, he has remained the guiding thinker in Iranian spiritualiry for generation after generation. Since the idea of a fourfold voyage is a tradition among Islamic mystics, Mullah Sadra takes it as the pattern upon which he structures his great summary of theosophical philosophg entitled 'High Wisdom Concerning the Four Spiritual Voyages'.
The first voyage is from the world of creatures towards Divine Being. In this, the philosopher grapples with general problems of physics, matter and form, and of substance and accident. At its culmination, the philosopher-pilgrim experiences fulfillment at the supersensible level of divine realities.
The second voyage moves from God, towards God, by means of God: one travels with God and in God. Here, the pilgrim never leaves the metaphysical plane; he is initiated into the ilahiyat, or divine sciences (the divinalia), and into the questions of the Divine Essence and the divine names and attributes.
The third voyage begins from God to a re-entry into the creaturely world, but by means of God and in God. In effect, this is an intellectual reversal of the first voyage, involving an initiation into the Hierarchy of Intelligences and the supersensible universes (the malakut and the jabarut).
Finally the fourth voyage begins in the creaturely world, and travels in this same world, accomplished this time by God or with God. Essentially, it is an initiation into knowledge of the soul, into self-knowledge. This is, par excellence, what these philosophers call "Eastern" knowledge ('ilm ishraqi) in the metaphysical sense of that adjective. It is an illustration of the maxim, "He who knows himself, knows his Lord," It is an initiation into the esoteric tawhid, the theomonism which maintains that only God truly is; and it is an initiation into the various symbols pertaining to the posthumous evolution of human beings.
Haydar Amoli, another great Iranian theosophical mystic, gave the following account of the fourfold voyage.
The first voyage moves towards God through the steps and dwellings of the soul, until it arrives at the limit of the manifest horizon (al-ufq al-mubin), which is the limit of the "station of the heart" (maqam al-qalb), at the threshold of the theophany of the divine names. The goal of this first voyage is the rending of the veils of plurality which hide the face of Unity.
The second voyage progresses from the manifest horizon towards the supreme horizon (al-ufq al-a'la) , which is the metaphysical level of the First Intelligence (first in the series of the Unities), that of Pluralizable Unity. During the progress of this second voyage, which moves towards God, the mystic gains access to the secret of the theophanies of the divine names. These are the theophanies through which the Divine Abyss, the Deus absconditus, manifests and creates itself as revealed God in the plurality of religious beliefs. This means that between each divine name and the human being through whom and by whom this name is revealed, there is a bond of reciprocal interdependence, analogous to that between a knight and his lord. The complementary inverse of the first voyage, this one rends the veil of Unity which hides the multitude of aspects related to esoteric knowledge.
The third voyage leads to a vision of all the divine names as forming a unitary totality ('ayn al-jam'); we might say a "unitude" or Unity (ahadiya) which is followed by no other unity, because it is the total unity of the totality. This voyage involves the falling away of the obstacles (taqyidat) which determine the pairs of opposites.
The fourth voyage then completes and reverses the third one. It consists of a return from the One to the Many, from God to creature, so as to attain the station of perfect equilibrium of the Balance. The multiplicity which was annihilated during the third voyage reappears, and finds its proper role here as the meta-existence (baqa') which follows annihilation (fana). Beings again appear in their plurality but this plurality no longer has the same meaning as it did for naive consciousness prior to the undertaking of the fourfold voyage. From here on, there is a simultaneity a coincidentia, between unitary fusion and separative distinction: between the extinction of God in the creature, and the extinction of the creature in God. This enables the inner eye of vision to contemplate Unity within the multitude of forms, and to contemplate the multitude of forms the very vision of Unity.
From: The Theme of the Voyage and the Messenger