Savage peoples are ruled by passion, civilized peoples by the mind. The difference lies not in the respective natures of savagery and civilization, but in their attendant circumstances, institutions, and so forth. The difference, therefore, does not operate in every sense, but it does in most of them. Even the most civilized peoples, in short, can be fired with passionate hatred for each other.

On War (ed. Princeton University Press, 2008) - ISBN: 9781400837403