The moment of betrayal is the worst, the moment when you know beyond any doubt that you've been betrayed: that some other human being has wished you that much evil.
The stranger is close to us, insofar as we feel between him and ourselves common features of a national, social, occupational, or generally human, nature. He is far from us, insofar as these common features extend beyond him or us, and connect us only because they connect a great many people.
"Randomized experiments are the gold standard for causal inference, but they are not always feasible."
You have to be willing to fail to be successful.