A rigorous reconstruction of scenario-based real choice making reveals the incompleteness of decision-modeling and the practical prevalence of uncertainty. Theoretically complete models conceal it. As a remedy a scenario-based procedure of coping with uncertainty can prescribe how the boundedly rational decision-maker should proceed from her or his internal point of view. Though models of substantive rationality cannot serve as guidance for decision-making under uncertainty, we can improve prescriptions for coping with uncertainties in view of evidence of substantive success or failure. Decision theory should aim for a reflective equilibrium incorporating internalist-prescriptive and externalist-descriptive aspects to turn good into better practice.