Fellow members of the .org,
I am about to write an essay about "the loss of humanity because of inurement to violence". The basis is an excerpt of a speech of Cicero, in which he complains about the loss of humanity in Roman society due to the civil wars and proscriptions.
I am looking for any kind of research on that topic.
If you know any sources from antiquity on this, although I doubt that there any or modern sources dealing with antiquity. Of interest is also the modern period, for example research on veterans from Vietnam, or even better if available, Iraq.
Sources have to be in English or German, I am also skilled at latin if there sources from antiquity.

If you have any additional questions, please ask.

Thanks in advance
GenosseGeneral