Plutarch, Sertorius
Bernadotte Perrin, Ed.

16. Sertorius, then, since all the peoples within the river Ebro were unitedly taking up his cause, had an army of great numbers, for men were all the while coming to him in streams from every quarter; but he was troubled by their barbaric lack of discipline and their overconfidence, since they called loudly upon him to attack the enemy and were impatient at his delay, and he therefore tried to pacify them by arguments. [2] But when he saw that they were impatient and inclined to force their wishes upon him unseasonably, he let them take their way and permitted them to have an engagement with the enemy in which he hoped that they would not be altogether crushed, but would be severely handled, and so made more obedient for the future. Matters turning out as he expected, he came to their aid, gave them refuge in their flight, and brought them safely back to their camp. [3] And now he wished to take away their dejection. So after a few days he called a general assembly and introduced before it two horses, one utterly weak and already quite old, the other large-sized and strong, within a tail that was astonishing for the thickness and beauty of its hair. By the side of the feeble horse stood a man who was tall and robust, and by the side of tine powerful horse another man, small and of a contemptible appearance. At a signal given them, the strong man seized the tail of his horse with both hands and tried to pull it towards him with all his might, as though he would tear it off; but the weak man began to pluck out the hairs in the tail of the strong horse one by one. [4] The strong man gave himself no end of trouble to no purpose, made the spectators laugh a good deal, and then gave up his attempt; but the weak man, in a trice and with no trouble, stripped his horse's tail of its hair. Then Sertorius rose up and said ‘Ye see, men of my allies, that perseverance is more efficacious than violence, and that many things which cannot be mastered when they stand together yield when one masters them little by little. [5] For irresistible is the force of continuity, by virtue of which advancing Time subdues and captures every power; and Time is a kindly ally for all who act as diligent attendants upon opportunity, but a most bitter enemy for all who urge matters on unseasonably.’ ¹ By contriving from time to time such exhortations for the Barbarians, Sertorius taught them to watch for their opportunities.