Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so.
Our shared values define us more than our differences. And acknowledging those shared values can see us through our challenges today if we have the wisdom to trust in them again.
When dealing with people, remember you are not dealing with creatures of logic, but with creatures bristling with prejudice and motivated by pride and vanity.