As there are different organs of senses, so there are five centers of inner perception. These centers are seats of the intuitive faculties. Two among them are of great importance: the heart and the head. If the Sufi training differs from that of the Yogis, it is in the training of both these centers together, by which the Sufi achieves balance. The head without the heart shows dry intellect. The heart without the head represents an unbalanced condition. Balance is the use of both these faculties. The Sufi training is based upon this principle.