While Adam Smith is best remembered for his work in economic theory, he was also a social philosopher, and in 1759 he published an acclaimed work titled The Theory of Moral Sentiments. This served to set down many of the logical and philosophical arguments that Smith later used in his magnum opus, The Wealth of Nations.
Smith depicted a moral state called sympathy, which he defined as the connection individuals feel with others when they share emotional reactions. He claimed that the desire for a sympathetic connection with others was the cornerstone of human interaction and society; without that desire, people would not gather into groups and form cohesive social units. The change in moral philosophy here is that human interaction is not based on altruism, as had been assumed for many years; the selfish desire to feel an emotional connection causes people to act in various ways, good or bad. A seemingly selfless act of charity actually serves the self; societal praise and the example to others is self-gratifying, not based in altruism, and allows the individual to feel a connection with others and a sense of personal achievement, regardless of the victim's eventual fate. Smith also commented that people could not be truly connected, but instead reacted to their own imagined idea of another person's emotional state. This gives another layer of disconnect between true sympathetic connection and an individual's personal idea of what makes himself (and others) happy.