Seguramente todos conocemos esta famosa cita:

Every individual is continually exerting himself to find out the most advantageous employment for whatever capital he can command. It is his own advantage, indeed, and not that of the society, which he has in view. But the study of his own advantage naturally, or rather necessarily, leads him to prefer that employment which is most advantageous to the society.

He generally, indeed, neither intends to promote the public interest, nor knows how much he is promoting it. By preferring the support of domestic to that of foreign industry, he intends only his own security; and by directing that industry in such a manner as its produce may be of the greatest value, he 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 of 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 than when he really intends to promote it. I have never known much good done by those who affected to trade for the public good.

Adam Smith, An Inquiry into the Nature and Causes of the Wealth of Nations (London: Edwin Cannan, 1904), Book IV, Cap. II.

Las famosas citas de Adam Smith reflejan una, y tal vez la más grande, de las contribuciones de la ciencia económica para la comprensión de los órdenes espontáneos que configuran lo que llamamos “sociedad”. Muestran, también, una visión optimista de la cooperación social, planteando que no solamente es ésta posible, sino que además es compatible con la búsqueda del interés personal.