Rationally Justifiable Play and the Theory of Non-cooperative Games.

This paper defines the concept of a justifiable strategy, that of a justification theory (which shows strategies to be justifiable) and that of a complete justification theory (which for every strategy shows whether it is justifiable or not). An impossibility result is proved, showing that there can be no complete justification theory that includes the assumptions of expected utility maximization, common knowledge, and caution. Copyright 1994 by Royal Economic Society.