Alexander halted his army on the heights; and taking with him some light-armed infantry and some cavalry, he passed part of the day in reconnoitring the enemy, and observing the nature of the ground which he had to fight on. Darius wisely refrained from moving from his position to attack the Macedonians on eminences which they occupied, and the two armies remained until night without molesting each other. On Alexander's return to his head-quarters, he summoned his generals and superior officers together, and telling them that he well knew that THEIR zeal wanted no exhortation, he besought them to do their utmost in encouraging and instructing those whom each commanded, to do their best in the next day's battle. They were to remind them that they were now not going to fight for a province, as they had hitherto fought, but they were about to decide by their swords the dominion of all Asia. Each officer ought to impress this upon his subalterns and they should urge it on their men. Their natural courage required no long words to excite its ardour: but they should be reminded of the paramount importance of steadiness in action. The silence in the ranks must be unbroken as long as silence was proper; but when the time came for the charge, the shout and the cheer must be full of terror for the foe. The officers were to be alert in receiving and communicating orders; and every one was to act as if he felt that the whole result of the battle depended on his own single good conduct. Having thus briefly instructed his generals, Alexander ordered that the army should sup, and take their rest for the night. Darkness had closed over the tents of the Macedonians, when Alexander's veteran general, Parmenio, came to him, and proposed that they should make a night attack on the Persians. The King is said to have answered, that he scorned to such a victory, and that Alexander must conquer openly and fairly. Arrian justly remarks that Alexander's resolution was as wise as it was spirited. Besides the confusion and uncertainty which are inseparable from night engagements, the value of Alexander's victory would have been impaired, if gained under circumstances which might supply the enemy with any excuse for his defeat, and encourage him to renew the contest. It was necessary for Alexander not only to beat Darius, but to gain such a victory as should leave his rival without apology for defeat, and without hope of recovery. The Persians, in fact, expected, and were prepared to meet a night attack. Such was the apprehension that Darius entertained of it, that he formed his troops at evening in order of battle, and kept them under arms all night. The effect of this was, that the morning found them jaded and dispirited, while it brought their adversaries all fresh and vigorous against them.