They immediately caused him to fall into a trance which lasted twenty-four hours. Ghazzali, who himself borrowed much from the Sufis, and was a diligent student of their doctrine, seeks to explain these strange phenomena on psychological grounds. He divides the ecstatic conditions which the hearing of poetical recitations produces into four classes. The first, which is the lowest, is that of the simple sensuous delight in melody. The second class is that of pleasure in the melody and of understanding the words in their apparent sense. The third class consists of those who apply the meaning of the words to the relations between man and God. To this class belongs the would-be initiate into Sufism; he has necessarily a goal marked out for him to aim at, and this goal is the knowledge of God, meeting Him and union with Him by the way of secret contemplation, and the removal of the veil which conceals Him. In order to compass this aim the Sufi has a special path to follow; he must perform various ascetic practices and overcome certain spiritual obstacles in doing so. Now when, during the recitation of poetry, the Sufi hears mention made of blame or praise, of acceptance or refusal, of union with the Beloved or separation from Him, of lament over a departed joy or longing for a look, as often occurs in Arabic poetry, one or the other of these accords with his spiritual state and acts upon him, like a spark on tinder, to set his heart aflame. Longing and love overpower him and unfold to him manifold vistas of spiritual experience. The fourth and highest class is that of the fully initiated who have passed through the stages above-mentioned, and whose minds are closed to everything except God. Such an one is wholly denuded of self, so that he no longer knows his own experiences and practices, and, as though with senses sealed, sinks into the ocean of the contemplation of God. This condition the Sufis characterise as self-annihilation (Fana). But he who is bereft of self-consciousness is none the less aware of what is without him; it is as if his consciousness were withdrawn from everything but the one object of contemplation, _i.e._, God. While he who is completely absorbed in the contemplation of the object seen is as little capable of theorising regarding the act of contemplation as regarding the eye, the instrument of sight, or the heart, the seat of joyful emotion. Just in the same way a drunken man is not conscious of his intoxication, so he who is drowned in joy knows nothing of joy itself, but only knows what causes it. Such a condition of mind may occur with regard to created things as well as with regard to the Creator Himself, only in the latter case it is like a flash of lightning, without permanence. Could such a condition of the soul last longer, it would be beyond the power of human nature to endure and would end in overwhelming it. So it is related of Taury that once in a meeting he heard this verse recited:--