What is a rational-choice (abbr. RC) explanation?

Requirements from Intentionality: A RC explanation must be an intentional explanation of behavior.

• (1) Given cognitions/beliefs C, behavior B is the best means to realize desire(s) D.
• (2) C and D caused B.
• (3) C and D caused B qua reasons (i.e. in the right way).
• However, in practice, a fully satisfactory intentional explanation of behavior is hardly attainable due to the practical difficulty of establishing the truth of (2) and (3) in an explanation. As an alternative, a second-best intentional explanation, which consists of establishing “motive, opportunity, knowledge, and ability”, is usually pursued in such cases.
• A sufficient explanation should facilitate predictions, whereas (1) alone cannot. This, again, shows that (1) alone is not an sufficient intentional explanation (but it can still be an insufficient, second-best one in practice nevertheless).

Requirements from Rationality: Showing that desires and beliefs, which behavior stem from, are rational

• (4) The set of beliefs C is internally consistent. (5) The set of desires D is internally consistent.
• (6) Given C, B is the best action with respect to the full set of weighed desires.
• (7) The relation between C, D, and E must satisfy (1b), (2b), (3b), and (N).

Optimality: the limitations of rational-choice explanations

There are at least two kinds of situation where a RG explanation is insufficient for an action.

1. INDIFFERENCE: when there are several options that are equally and maximally good
2. INCOMPARABILITY: when there is no "best" option at all