How Bioethics and Case Law Diverge in Assessments of Mental Capacity: An Argument for a Narrative Coherence Standard.

Clinical assessments of mental capacity have long been guided by four basic cognitive criteria (understanding, appreciation, ability to reason, communication of decision), distilled directly from widespread legal precedent in common law cases of informed consent and refusal. This article will challenge the sufficiency of these legal criteria at the bedside on the assertion that clinicians and bioethicists who evaluate decisional capacity face questions far deeper than the mere presence or absence of a patient's informed consent. It will then present an additional standard beyond the existing cognitive criteria - to be called the Narrative Coherence Standard - that may begin to bridge the gap between the existing legal standards and higher-order bioethical priorities. This standard will be treated with a philosophical argument for its use, as well as a detailed exploration of its technical components and conceptual underpinnings.