The Farmer and the Snake农夫与蛇   

ONE WINTER a Farmer found a Snake stiff and frozen with cold.  He had compassion on it, and taking it up, placed it in his bosom.   The Snake was quickly revived by the warmth, and resuming its  natural instincts, bit its benefactor, inflicting on him a mortal  wound. "Oh," cried the Farmer with his last breath, "I am rightly   served for pitying a scoundrel."   

The greatest kindness will not bind the ungrateful.      

冬天，农夫发现一条蛇冻僵了，他很可怜它，便把蛇放在自己怀里。蛇温暖后，苏醒了 过来，恢复了它的本性，咬了它的恩人一口，使他受到了致命的伤害。农夫临死前说：“我 该死，我怜悯恶人，应该受恶报。”    

这故事说明，即使对恶人仁至义尽，他们的邪恶本性也是不会改变的。