slavery

I was reading some articles about slavery in America, in the past of course, and found this.
I couldn't have conceived such shocking image.
Very objectively a thought just ran through my mind:The most developed human specie, sorry I couldn't think of other word - help me, push slavery to its peak.
Then part of them, the highest developed minds - I think, fight to abolish it. 
The result is a new stage of the development of the society.


Isn't it the way how things go on?
Another example is about our hot topic "global environmentl problem".
The leading parts of human beings gave birth to the industrial revolution, whose drawback is the enviromental damage.
Now, it's the leading parts, mostly those that I mention above, are the leaders in the fight to save our planet ?

Isn't it a little similar to Yin-Yang theory ?

Same things have been happening with homosexual issue, rich-poor countries issue, discrimination issue...etc. almost everything.

Just love to watch and see.