As regards action, he ought above all things to keep his men well organized and drilled, to follow incessantly the chase, by which he accustoms his body to hardships, and learns something of the nature of localities, and gets to find out how the mountains rise, how the valleys open out, how the plains lie, and to understand the nature of rivers and marshes, and in all this to take the greatest care. Which knowledge is useful in two ways. Firstly, he learns to know his country, and is better able to undertake its defence; afterwards, by means of the knowledge and observation of that locality, he understands with ease any other which it may be necessary for him to study hereafter; because the hills, valleys, and plains, and rivers and marshes that are, for instance, in Tuscany, have a certain resemblance to those of other countries, so that with a knowledge of the aspect of one country one can easily arrive at a knowledge of others. And the prince that lacks this skill lacks the essential which it is desirable that a captain should possess, for it teaches him to surprise his enemy, to select quarters, to lead armies, to array the battle, to besiege towns to advantage. Philopoemen,[1] Prince of the Achaeans, among other praises which writers have bestowed on him, is commended because in time of peace he never had anything in his mind but the rules of war; and when he was in the country with friends, he often stopped and reasoned with them: “If the enemy should be upon that hill, and we should find ourselves here with our army, with whom would be the advantage? How should one best advance to meet him, keeping the ranks? If we should wish to retreat, how ought we to pursue?” And he would set forth to them, as he went, all the chances that could befall an army; he would listen to their opinion and state his, confirming it with reasons, so that by these continual discussions there could never arise, in time of war, any unexpected circumstances that he could not deal with. [1] Philopoemen, “the last of the Greeks,” born 252 B.C., died 183 B.C.