… is from page 223 of Robert Wright’s wonderful 1994 book, The Moral Animal :
Even urban gang members have people who can trust them. And even scrupulously polite Victorian men went to war, convinced of the justness of the death they dished out. Moral development is often a question not just of how strong the conscience will be, but of how long a reach it will have.
This important insight does not imply that each of us should love and care for strangers as much as we love and care for our family members and close friends. Such sentiments (and even more obviously, actions consistent with those sentiments) are humanly impossible. What Wright’s insight does suggest is that each of us should be better at recognizing the humanity of all people, regardless of where those people live and of which sovereign rulers issue their passports. The same civil sentiments that we have for strangers in our own countries are civil sentiments that we ought to have for strangers in other political jurisdictions.