Some say the desire-nature is a substance, placed in the body, similar to the Soul. Others say it is a quality of the body, similar to life. But all take it as the source of evil qualities and acts. These evils are grouped into: (a) sins, (b) qualities, e. g. pride, envy, anger. The former pertain more to the outer man, the latter more to the inner man. The former are purified by ascetic practices, the latter by Taubâh (or Turning) . . . .

It is said that the desire-nature and the Soul are both mysterious entities in the body, corresponding to demons and angels, hell and heaven in the macrocosm;—the one being the centre of evil, the other the centre of Good. There is no help against the desire-nature save in ascetic practices.

Man is the epitome of the whole Universe, and is composed of the Soul, the desire-nature and the body. He bears the characteristics of all the worlds. The earth, water, fire and air of this world appear in his body as the four humours: blood, phlegm, melancholy and bile. Other worlds are not less vividly marked in him. The Soul leads him to heaven, being its image; the desire-nature leads him to hell, being its image.

Bû Alî saw his desire-nature in the form of a hog. He wished to kill it, but it said to him, “Do not trouble thyself: I belong to the Army of God, thou canst not annihilate me.”

Mohammad Nûrî speaks of his desire-nature coming out of his throat in the form of a miniature fox. “I knew it was the desire-nature, so I put it under my feet and began to trample upon it. It grew the larger and the stronger. I said, ‘Pain and torture destroy all things, but they simply aid your growth!’ It said, ‘This is due to the fact of my constitution being the other way: what is pain for others is pleasure for me.’”

Abul Abbâs saw it in the form of a yellow­ish dog. When he attempted to turn it out, it came underneath the skirts of his garment, and disappeared.

Abul Qâsim saw it in the form of a serpent.

Another Dervesh saw it in the form of a mouse, and asked who it was. It said, “I am the death of the heedless and the salvation of the Divine Friends. If I were not, they would turn proud of their purity and noble deeds.”

These stories go to show that the desire-nature is a corporeal being—not a quality—albeit it is endowed with qualities. It should be subdued by ascetic practices, but it cannot be completely destroyed in its essential nature. There need not be any fear from its existence, when it has been subdued by the disciple. . . . This dreary forest cannot be crossed save with the help of the Divine Grace and under the protection of a Master of Compassion.—Letter 81.