Aristotle: A man would be regarded as a bloodthirsty monster if he were to make war just to produce battles and slaughter
From Nicomachean Ethics
Translated by J.A.K. Thomson
Now the practical virtues find opportunity for their exercise in politics and in war, but these are occupations which are supposed to leave no room for leisure. Certainly it it is true of the trade of war, for no one deliberately chooses to make war for the sake of making it or tries to bring about a war. A man would be regarded as a bloodthirsty monster if he were to make war on a friendly state just to produce battles and slaughter.
Sailors combine for the purpose of making money from the profits of a voyage, soldiers join forces in order to exploit the profits of war, whether they are hoping for loot or conquest or the capture of a city.