All prescriptive decision-making epistemologies are rooted in worldviews. If the worldview assumptions of an epistemology are not congruent with the world in which decisions are to be made, that epistemology ought not to be granted prescriptive authority. The rationalistic wortdview is described in two versions, classic and modified, together with the prescriptive decision-making epistemologies that depend on them. The classic version is firmly grounded in the assumptions of the 18th century Enlightenment; the modified version is more pragmatic in orientation. Both emphasize order, clarity, empiricism, and logical analysis. An alternative, nonrationalistic worldview concerns itself with novelty, incongruity, intuition, and subjective awareness. Foreign-policy decision theorists routinely assume that the foreign-policy world contains a mixture of rationalistic and nonrationalistic elements but are reluctant to grant decision makers the intuitive and subjective capabilities that, together with logical thinking and empirical observation, are necessary to operate in such a world. This reluctance inhibits the development of a prescriptive decision-making epistemology suitable for a mixed world. Analytical psychology provides one avenue for exploring the prescriptive implications of a more comprehensive psychology. It is clear that in a world with important nonrationalistic elements, true rationality requires that nonrationalistic capabilities and skills be both appreciated and developed.