December 6, 2004
Every individual...intends only his own gain, and he is in this, as in many other cases, led by an invisible hand to promote an end which was no part his intention. Nor is it always the worse for the society that it was no part of it. By pursuing his own interest he frequently promotes that of the society more effectually that when he really intends to promote it.
From The 101 Greatest Business Principles of All Time edited by Leslie Pockell with Adrienne Avila