Plutarch, De garrulitate
Goodwin, Ed.

I know both when and where my tongue to hold,
And when with safety to be freely bold.
¹

For they that are brought up under a truly generous and royal education learn first to be silent, and then to talk. And therefore King Antigonus, when his son asked him when they should discamp, replied, What! art thou afraid of being the only man that shall not hear the trumpet? So loath was he to trust him with a secret, to whom he was to leave his kingdom; teaching him thereby, when he [p. 232] came to command another day, to be no less wary and sparing of his speech. Metellus also, that old soldier, being asked some such question about the intended march of his army, If I thought, said he, that my shirt were privy to this secret, I would pull it off and throw it into the fire. Eumenes also, when he heard that Craterus was marching with his forces against him, said not a word of it to his best friend, but gave out all along that it was Neoptolemus; for him his soldiers contemned, but they admired Craterus's fame and virtue; but nobody knew the truth but Eumenes himself. Thereupon joining battle, the victory fell to their side, and they slew Craterus, not knowing whom he was till they found him among the slain. So cunningly did taciturnity manage this combat, and conceal so great an adversary; so that the friends of Eumenes admired rather than reproved him for not telling them beforehand. For indeed, should a man be blamed in such a case, it is better for him to be accused after victory obtained by his distrust, than to be obliged to blame others after an overthrow because he has been too easy to impart his secrets.