Adam Smith's shorthand for the ability of the free market to allocate factors of production, goods and services to their most valuable use. If everybody acts from self-interest, spurred on by the profit motive, then the economy will work more efficiently, and more productively, than it would do were economic activity directed instead by some sort of central planner. It is, wrote Smith, as if an "invisible hand" guides the actions of individuals to combine for the common good. Smith recognised that the invisible hand was not infallible, however, and that some government action might be needed, such as to impose antitrust laws, enforce property rights, and to provide policing and national defense.