It's easy to see from far away what is bad, people all over the western world can point at Hitler in their history books as an example of absolute evil. But then we'd be missing the complete picture, which is so much worse if you cling to a traditional view of good and evil. Normal school curriculum (at least where I'm from) does not teach about the horrific things Belgium did in the Congo up until the 1960s Or any of the other decimations/genocides caused directly or indirectly as a result of occupation by the various colonial powers. Or all the terrible things our ancestors did even further in the past when news spread so much slower or not at all.
There was a Byzantine king named Basil. Who, after defeating a Bulgarian army and capturing a number of their soldiers, blinded 99 out of every 100 captured soldiers and sent them back to Bulgaria to cripple their economy and to sabotage future war efforts. Man is a savage evil creature imo. I don't think we ever truly can change. The civilization I and many others enjoy in the western world is a fragile thing I think. And if we can't make it stick and spread, and I don't think I can, then when the troubles get too bad we'll be back to savagery soon enough, or not as the bomb is still hanging above our heads even if it doesn't feel like that any more.