Irrational People Have Rights Too : Moving Beyond Rationality in Decisional Capacity Assessment

The dominant method of assessment for decisional capacity, the "four abilities" model, relies heavily on the reasoning abilities of the patient. This paper argues that the rational thinking required of medical patients to preserve their autonomy is a legal anomaly that is highly inconsistent with other areas of law, including the rules related to high-stakes social and economic decisions. The model also denies autonomy to a subset of individuals who possess strongly held and longstanding preferences regarding their care but are unable to explain the bases for these preferences in a manner satisfactory to physicians. Following up on recent challenges to the "four abilities" model by Fogal and Schwan, among others, this paper argues for an alternative model that embraces a values-based approach when such values are known and a "consistent preferences" approach when they are not known.