But theres a serious point here: the shifting of an Overton window often happens gradually, and we readjust to its new range very quickly,9 so there is risk in allowing ourselves to do anything we know is bad just because we want to. In fact, even with good intentions and level heads, if we give in to our lesser instincts too often theres a far more likely outcome than we become black market weapons dealers. Its simply that we become selfish. We start to believe that our own right to do whatever we want, whenever we want to do it, is more important than anything else, and thus our sense of morality concerns only our own happiness or pain.

How to Be Perfect by Michael Schur