The idea of the Sufi is that life lives and that death dies. In other words: to life there is no death, and to death there is no life. But this way of attaining to the certainty that life is continuous, is not only an intellectual one. For by studying all the philosophies and metaphysics all through his life, a man may prove to himself by reasoning that there is continuity of life; yet this realization gained by effort of mind will still not give him the feeling of certainty which he would wish to have. The Sufi, therefore, practices the process by which he is able to touch that part of life in himself which is not subject to death; and by finding that part of life he naturally begins to feel the certainty of life. It makes him more certain of life than of anything else in the world, for he sees the changeability and limitation of all things. Everything that is constructed is subject to destruction; everything that is composed is subject to decomposition; everything born is subject to death. In finding that life he finds his own self, and as that is the real life, everything else that he knows about life begins to lose its importance.