After setting forth his problem in this formal and minutely systematic manner, Buddha goes still further. If man will free himself from pain, pain must be annihilated. In order to attain this end the cause of it must be discovered. This cause is desire (_trishna_). Desire is the passion which man feels to attain content and satisfaction, the ever-renewed impulse to have pleasant sensations and avoid the unpleasant, which is sometimes satisfied, but more frequently the reverse.[435] If pain is to be annihilated, desire must be annihilated. The cause of desire is sensation, and if we inquire into sensation we find on reflection that it is something transitory. When we have the sensation of what is pleasant, the sensation of what is unpleasant does not exist any longer, and _vice versâ_; sensation therefore is subject to annihilation, and in consequence is not permanent, nor has it any real existence. Sensation is, as the Buddhists say, "empty and without substance."[436] It does not belong to the nature of the soul. As soon as we can say of sensation or of any other object, "I am not this, this is not my soul," we are free from it; and when we have attained this knowledge, no sensation whatever, nor conception, nor perception, exercises any charm over man.[437] If this knowledge is acquired, man is in a position to "unbind" himself from sensation, and as soon as he has unbound himself from sensation he has liberated himself from it; he feels neither inclination nor disinclination; neither restlessness nor pain, nor despair;[438] his heart no longer clings to the "causes of content, which were at the same time the causes of discontent, more closely than drops of rain to the leaf of the lotus."[439] If we go further in this direction and instruct ourselves by meditation that even the senses, eyes, ears, etc., are perishable,[440] that the body is subject to birth and death, and consequently that it is something transitory and without permanence, we are freed from the body and henceforth merely contemplate it. From this point of view we perceive that the body of a man is his executioner; and in the senses we recognise desolated villages, in the things of the external world, the enemies and plunderers which perpetually attack men, disquiet and ravage them.[441] Whatever a man has hitherto felt of dependence and inclination, of care and submissiveness to the body; whatever content and satisfaction he has felt through the body in the body,--is now annihilated by the knowledge that the body is nothing real, that it is not the soul. When we have reached this point, pain is removed, because the cause of it is removed; man is no longer dazzled by desire, and therefore no longer distressed; he is now lord of his senses and lord of himself. Freed from all bonds, from all inclinations to, and dependence on, the world, he feels the happiness and joy of repose.[442]