Lieber, F. (1889). Chapter III [5]. In F. Lieber, Manual of political ethics, Part 2: Political ethics proper (for the use of colleges and students at law) (pp. 629-668). Boston, MA, US: Charles C Little and James Brown.
http://dx.doi.org/10.1037/14235-021
In this last chapter it is proposed to give a few remarks on War, as connected with our subject. I am well aware that the whole subject of war belongs properly to the so called law of nations and international ethics; yet so much has been advanced of late regarding war as affecting the morality of the individual, and so many cases, to be decided on ethic ground by the individual, necessarily happen in every war, that I feel obliged to add this chapter to the present work, although international ethics in general have been excluded from it. I shall confine myself, however, to some remarks touching in general the admissibility of war among rational and moral beings, and some respecting the conduct of the individual who takes part in a war, excluding from our inquiry, the whole important field of the law of war proper. (PsycINFO Database Record (c) 2016 APA, all rights reserved)