Early Man

I'm studying in my college(Faculty of Law)a book named:"History of Canonical and Social Sysyems"....On reading it few days ago,I read two paragraphs describing early Man when he has no Law,or no rules to organize his life…
Here you're the translation of them and you can deduce what I want to say but I just repeat that it's early Man who lived in caves and has no rules..

"..and in relations outside the group,force was the basic rule,and foreigner was considered as an enemy and it was legal to kill and steal his money.And in forming this philosophy,the group was bringing up it's individuals on not respecting rights of other groups and plant from childhood habit of war and fighting against other groups.
And this extension of using force backs to more than one reason which represent nature of general status these times;as not ripening of feeling of respecting rights of others,on the other hand,absence of rules which forbid using force…"

"..there is no right to foreigner of the family,as he has no relation between him and them;as he is different in blood,and religion,and don't share them their economy,and is different in their habits and traditions.But in contrary he was considered as the enemy who is legal to be killed just like as a wild animal;as a result,stealing money of the other wasn't considered as a crime,and don't bring any guilt or shame to it's doer,but it was an honor way,and raiding was a source for pride and revenging was a must that honor necessitates."