There are hearts with many different qualities, like water with different chemical substances: those who have suffered, those to whom life has taught patience, those who have contemplated. They all represent one or other kind of the water that heals, and so do their personalities. People who have had deep experiences of any kind, of suffering, of agony, of love, of hate, of solitude, of association, of success, of failure, all have a particular quality, a quality which has a special use for others. And when a person realizes this, he will come to the conclusion that whatever has been his life's destiny, his heart has prepared a chemical substance through sorrow and pain, through joy or through pleasure, a chemical substance that is intended for a certain purpose, for the use of humanity, and that he can only give it out if he can keep his heart awakened and open. Once it is closed, once it is frozen, man is no longer living. It does not matter what he has gone through, for even the worst poison can be of some use. There is no person, however wicked, who is of no use, if only he realizes that the first condition for being useful to humanity is to keep his heart open.