In English
Man can change his nature by disciplined effort
Man alone can rise through effort to higher stages of spiritual evolution. No other animal can do so. Animal tamers of the circus can train a tiger to perform various tricks, but they cannot change its nature. They cannot make it live on grass and completely deprive it of meat. But man is different. His nature can be changed by means of his own disciplined effort. He can control, by his will, the 'evil thoughts and ideas that arise in his mind. This is why birth 'as a human being is considered a rare gift.