What is humanity?

Is it to being polite with each other, and saying 你好我好大家好?  I think that is politeness.  

Is it to step in/up to help others when needed? I think it's friendship.

Is it to apple-polish others to get benefits or favors? I think that is sweet-talk.

But when I read this story in 北岛's book, I was very moved and I'm very sure it is true humanity:

(Background: the story happened during 文革，in 北京四中, one of the best all-boy high schools at the time, the ages of the students there were all 18 and under).

"因写中篇小说《晚霞消失的时候》而出名的刘辉宣（笔名礼平）回顾说：“那时我们学校（四中）有一个群众组织叫’新四中公社‘。取巴黎公社之意，是我们的对立面。他们当中有一个同学叫杨小青，和我们积怨甚深，见了面就怒目而视。后来有一次外校的武斗打进了我们学校，混战中我陷入重围（注：那时是会有生命危险的），杨小青拼着命将我救了出来。但事后我们见了面还是怒目而视，管这叫‘坚持原则’。但我心里却尊重他，当时就敬重他 。。。”

With this type of humanity, what can't we overcome? ;-)