"How selfish soever man may be supposed, there are evidently some principles in his nature, which interest him in the fortune of others, and render their happiness necessary to him, though he derives nothing from it except the pleasure of seeing it."
What kind of strength do you think it is for a human being to genuinely rejoice in someone else's joy?
The 'Invisible Hand' Economist's First Book Was About Sympathy?
Adam Smith was a professor of moral philosophy at the University of Glasgow during the Scottish Enlightenment. Seventeen years before The Wealth of Nations (1776), he wrote The Theory of Moral Sentiments (1759), arguing that we learn morality through 'sympathy'—imagining ourselves in another's place.
He was famously absent-minded; one story has him walking about fifteen miles in his nightgown, lost in thought. He kept revising The Theory of Moral Sentiments until just before his death, producing a sixth edition, and at the end of his life had his friends burn most of his unfinished manuscripts.