I know that I have posted this before, but I just completed a unit on ethics and wanted to share.
I tell students that they have to get to the point where acting ethically is not a decision but instinct. You have to inherently derive joy from doing the right thing. Adam Smith in the Theory of Moral Sentiments, which preceded The Wealth of Nations, said that people will be inherently moral because it brings them joy to do so. Therefore, the basis of the free market economic theory is that everyone, inherently, as if "guided by an invisible hand," acts morally.
Ultimately, it is all about being part of the Brotherhood of Man:
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