The invisible hand is a metaphor used by the Scottish moral philosopher Adam Smith that describes the inducement a merchant has to keep his capital, thereby increasing the domestic capital stock and enhancing military power, both of which are in the public interest and neither of which he intended.
Some later authors have broadened this to imply the unintended greater social impacts brought about by individuals acting in their own self-interests.
Smith originally mentioned the term in his work Theory of Moral Sentiments in 1759, but it has actually become known from his main work The Wealth of Nations, where the phrase is mentioned only once, in connection with import restrictions.