Edward Hale 
The Fall of the Stuarts [EPUB ebook] 

Wars destroy the morals of mankind by habituating them to refer everything to force, and by necessitating them so often to dispense with the ordinary suggestions of sympathy and justice. This is true of wars in general; but the demoralizing effect is much greater if wars are civil wars; or religious wars–wars, that is, between fellow-citizens to serve the ends of some political party, or to enforce the observance of some political truth; or wars between fellow-Christians to force all to follow some religious creed. Moral virtues are in these cases uprooted; military virtues, which may exist in the most depraved man or state, flourish.