There are basic prerequisites to rational social action by an individual or group. The actor must make rational calculations about the ways in which the attainment of his goals can be maximized in the real world. Codification is the reduction and unification to more or less self-consistent principles of hitherto disorderly and unsystematized propositions. It is convenient to distinguish between the codification of knowledge about fact and the codification of social norms, or a social code. Rational calculation is a burden, too. And there is a stubborn paradox in the fact that many important prime goals cannot be achieved by conscious calculation: for these goals calculation must be unconscious. Every literate person could list many kinds of decisions where so little is known that calculations cannot be rational. The central obstacle to rational calculation is the difficulty of weighing the relevant alternatives and deciding which is most valuable.