[31] Then the father said, "My son, we are told that in the days of our forefathers there was such a teacher once. This man did actually teach his boys righteousness in the way you suggest, to lie and not to lie, to cheat and not to cheat, to calumniate and not to calumniate, to be grasping and not grasping. He drew the distinction between our duty to friends and our duty to enemies; and he went further still; he taught men that it was just and right to deceive even a friend for his own good, or steal his property. [32] And with this he must needs teach his pupils to practise on one another what he taught them, just as the people of Hellas, we are told, teach lads in the wrestling-school to fence and to feint, and train them by their practice with one another. Now some of his scholars showed such excellent aptitudes for deception and overreaching, and perhaps no lack of taste for common money-making, that they did not even spare their friends, but used their arts on them. [33] And so an unwritten law was framed by which we still abide, bidding us teach our children as we teach our servants, simply and solely not to lie, and not to cheat, and not to covert, and if they did otherwise to punish them, hoping to make them humane and law-abiding citizens. [34] But when they came to manhood, as you have come, then, it seemed, the risk was over, and it would be time to teach them what is lawful against our enemies. For at your age we do not believe you will break out into savagery against your fellows with whom you have been knit together since childhood in ties of friendship and respect. In the same way we do not talk to the young about the mysteries of love, for if lightness were added to desire, their passion might sweep them beyond all bounds." [35] "Then in heaven's name, father," said Cyrus, "remember that your son is but a backward scholar and a late learner in this lore of selfishness, and teach me all you can that may help me to overreach the foe." "Well," said the father, "you must plot and you must plan, whatever the size of his force and your own, to catch his men in disorder when yours are all arrayed, unarmed when yours are armed, asleep when yours are awake, or you must wait till he is visible to you and you invisible to him, or till he is labouring over heavy ground and you are in your fortress and can give him welcome there." [36] "But how," asked Cyrus, "can I catch him in all these blunders?" "Simply because both you and he are bound to be often in some such case; both of you must take your meals sometime; both of you must sleep; your men must scatter in the morning to satisfy the needs of nature, and, for better for worse, whatever the roads are like, you will be forced to make use of them. All these necessities you must lay to heart, and wherever you are weaker, there you must be most on your guard, and wherever your foe is most assailable, there you must press the attack."