There is little warrant for the belief that we know the laws of history well enough to make projections of any great reliability. Most of the turning… - Kenneth Arrow

As we see it, a choice is not something you do today in isolation; it is part of a plan that includes some choices to be made in the future.

If the total number of alternatives is two, the method of majority decision is a social welfare function which satisfies Conditions 2–5 and yields a social ordering of the two alternatives for every set of individual orderings.

Decision theory, as it has grown up in recent years, is a formalization of the problems involved in making optimal choices. In a certain sense — a very abstract sense, to be sure — it incorporates among others operations research, theoretical economics, and wide areas of statistics, among others.