Even Ricardo's most famous accomplishment, the law of comparative advantage in foreign trade, is incomplete, though not wrong. - Kenneth Arrow

I expect that ethical codes and informal nonprice organizations will continue to evolve where needed, for example in the control of product quality, to permit transactions which would be impossible because of differential information in markets where all individuals behaved in a purely selfish manner. The evolution of ethical codes is facilitated by the fact that productive units are organizations, not individuals, and individuals are mobile among these organizations.

The uncertainty of the future is inescapable, one must think about it and arrive at plans for action. A statement attributed to a number of thinkers is, "Prediction is very difficult, especially of the future." Postdiction, knowing what went on in the past, is also difficult. The past, however, is our basis for understanding the future.

The Austrian a priori dogmatism (von Mises, especially; Hayek, to a lesser degree).