An interesting question first posed by the controversial historian A.J.P. Taylor in his seminal thesis “Moo ? A Warning From History”. His central tenet was that the very harshness of war was the catalyst for these deep philosophical debates but his ideas sparked great discussion amongst the cognescenti of the era.
In more recent times Germaine Greer has offered a female perspective in her treatise “Moo ? A Non-Gender-Oriented Approach” but then she is only a girl so why listen ?