Because there is nothing proportionate between the armed and the unarmed; and it is not reasonable that he who is armed should yield obedience willingly to him who is unarmed, or that the unarmed man should be secure among armed servants.

Because, there being in the one disdain and in the other suspicion, it is not possible for them to work well together.

And therefore a prince who does not understand the art of war, over and above the other misfortunes already mentioned, cannot be respected by his soldiers, nor can he rely on them.
He ought never, therefore, to have out of his thoughts this subject of war, and in peace he should addict himself more to its exercise than in war; this he can do in two ways, the one by action, the other by study.
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.