Let me clinch my argument by examples: no chariot can travel fast if the horses in the team are slow, or run straight if they will not be ruled; no house can stand firm if the household is evil: better empty walls than traitors who will bring it to the ground.
[27] "And be sure, my friends," he added, "the removal of the bad means a benefit beyond the sheer relief that they are taken away and will trouble us no more: those who are left and were ripe for contagion are purified, and those who were worthy will cleave to virtue all the closer when they see the dishonour that falls on wickedness." [28] So Cyrus spoke, and his words won the praise of all his friends, and they set themselves to do as he advised.
But after that Cyrus began to jest again.

His eye fell on a certain captain who had chosen for his comrade at the feast a great hairy lad, a veritable monster of ugliness, and Cyrus called to the captain by name: "How now, Sambulas?
Have you adopted the Hellenic fashion too?
And will you roam the world together, you and the lad who sits beside you, because there is none so fair as he ?" "By heaven," answered Sambulas, "you are not far wrong.

It is bliss to me to feast my eyes upon him." [29] At that all the guests turned and looked on the young man's face, but when they saw how ugly it was, they could not help laughing outright.

"Heavens, Sambulas, tell us the valiant deed that knit your souls together! How has he drawn you to himself ?" [30] "Listen then," he answered, "and I will tell you the whole truth.

Every time I call him, morning, noon, or night, he comes to me; never yet has he excused himself, never been too busy to attend; and he comes at a run, he does not walk.