知识
It takes considerable knowledge just to realize the extent of your own ignorance.
If facts, logic, and scientific procedures are all just arbitrarily "socially constructed" notions, then all that is left is consensus--more specifically peer consensus, the kind of consensus that matters to adolescents or to many among the intelligentsia.
The ideas of economists and political philosophers， both when they are right and when they are wrong， are more powerful than is commonly understood. Indeed the world is ruled by little else. Practical men， who believe themselves to be quite exempt from any intellectual influence， are usually the slaves of some defunct economist.