Decisional capacity assessments are a routine yet critical component of healthcare practice worldwide, profoundly influencing the trajectory of patients' lives. These evaluations carry significant psychological and ethical weight, as they determine the extent to which individuals should be granted the authority to make decisions about their own care. Formal assessments are designed to evaluate whether a patient's decision-making autonomy may be justifiably limited, potentially resulting in restrictions not only on their choices, but to the information provided to them for own rational deliberation. Decisional Capacity: Medical and Philosophical Perspectives offers a comprehensive, interdisciplinary resource for clinicians navigating these complex and consequential determinations.This volume highlights the vital role ethicists play in supporting clinicians as they navigate the complex challenges of assessing decisional capacity and making ethically justifiable care decisions. Philosophers and theorists further contribute by examining the conceptual and logical foundations of standard assessment procedures, exploring how these determinations intersect with broader questions about autonomy and human dignity. Decisional Capacity: Medical and Philosophical Perspectives features sixteen chapters authored by leading experts across psychiatry, clinical psychology, neurology, oncology, philosophy, bioethics, and law. Despite the wide-reaching relevance of decisional capacity, this is the first interdisciplinary volume to offer both practical clinical guidance and critical philosophical analysis, providing a uniquely comprehensive resource for professionals across the healthcare spectrum.