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.

Ch. 14 - The Prince (1513)