From: Parisi Daniela But, when you refer to choice, do you mean a rational explanation of the regularities which characterise phenomena? In this case, as Carstensen is suggesting,is a matter of relationships between choices and framework; consider, for example, moral, religious or social sanctions that support the rule. That's true because rationality is not only rationality of having a rule, but also rationality of a rule itself. Picking up on Daniela's point about moral, religious and social sanctions and the rationality of the rule itself, this seems to move the debate to the question of who decides whether the rules are rational or not? For example, are suicide bombers rational? Is this optimising behaviour subject to the relevant constraints? Jim Thomas