Sextus Iulius Frontinus, vir consularis de re militari

...and to perform the remaining duties with more obedience.

How an untimely demand for battle may be inhibited. Chap. x.

Quintus Sertorius, because he had learned by experience that he was unequal to the entire Roman army, in order to teach the barbarians also who were demanding battle inconsiderately, brought into sight two horses: one powerful, the other very scrawny. He brought forward two young men, similarly affected, one robust and one slender, and commanded the robust one to pull off the entire tail of the powerful horse, while to the slender one, he commanded that he pull the tail of the stronger horse by single hairs. When the slender one had done what was commanded, the most robust one struggled in vain with the tail of the weak horse. "Now," said Sertorius, "I have shown you by this example, soldiers, that the Roman cohorts are insuperable to those attacking them all at once, but he who attacks them by parts will lacerate and tear them." The same man, when he saw his own men demanding the signal for battle inconsiderately and believed they would break the command if they did not engage, permitted a squadron of cavalry to go to harass the enemy and sent others to help the struggling ones. And thus he received them all, and having kept both safe and without harm, he showed what the outcome of the requested battle would have been; he used them as most obedient thereafter. Agesilaus the Lacedaemonian, when he had placed his camp above the bank against the Thebans and realized the enemy's force was much larger and therefore wanted to keep his own men from the desire of deciding the issue, said that the god had responded that he was ordered to fight from the hills. And thus, having placed a small guard at the bank, he moved onto the hills. The Thebans, interpreting this as fear, crossed the river and, when they had easily pushed aside the guard, pursued the others and were defeated by the few, contrary to the inequality of the terrain. Scorio, the leader of the Dacians, when he knew the Roman people were divided by civil arms but still thought they should not be tested because they might coalesce in concord against the citizens through an external war, brought two dogs together in the sight of his people. While they were fighting most fiercely among themselves, he showed them a wolf, which the dogs immediately attacked, having set aside their anger toward each other. By this example, he prohibited the barbarians from an attack that would have been profitable to the Romans.

How an army is to be incited to battle. Chap. xi.

Fabius and Caius Manilius, the consuls, when the army was refusing battle against the Etruscans due to sedition, feigned hesitation until the soldiers, compelled by the insults of the enemy, demanded battle and swore they would return from it as victors. Fulvius Nobilior, when he had a necessity to fight against the numerous army of the Fannitii who were swollen with successes with few forces, feigned that one legion of the enemy had been corrupted by him for treachery. He commanded, for the proof of this matter, that the tribunes and the first ranks and the centurions confer as much money or gold and silver as each had, so that the reward could be presented to the traitors; he promised to those who had brought it that he would give ample rewards in addition upon the completion of victory. This persuasion brought alacrity and confidence to the Romans, and from there, a famous victory was accomplished immediately upon joining the war.