The mind is composed of five faculties. Even as our hand has five fingers, the physical world has five chief elements, which constitute it. As ether is an element separate from earth, water, fire, and air, and yet contains all these elements, so is the faculty which we call heart, a faculty separate from the remaining four; and yet it contains the four faculties within itself.

The special work of the heart is to feel and to produce emotions out of itself. The second faculty is mind. Its work is to think and to produce thoughts. The third faculty is memory. Its work is to collect and to supply impressions. The fourth is reason. Its work is to discriminate and to decide things. The fifth faculty is the ego, which makes one think of one's own person, and all else as a separate entity.

The word, 'heart,' in metaphysics denotes the main center of the mental plane. The piece of flesh which we term heart is the sensitive part in us, which feels the effect of all joy and pain before any other organ. From this center, the breath carries on the work of spreading all energy throughout the physical body. That is why the Sufi works through this center in the physical body when he wishes to impress his absolute self with a certain thought. But high development lies in purifying the five faculties before mentioned by the mystical process and in mastering them.