Disorders of Consciousness (Do Cs) raise difficult and complex questions about the value of life for persons with impaired consciousness, the rights of persons unable to make medical decisions, and our social, medical, and ethical obligations to patients whose personhood has frequently been challenged and neglected. Recent neuroscientific discoveries have led to enhanced understanding of the heterogeneity of these disorders, and focused renewed attention on the medical and ethical problem of misdiagnosis. This book examines the entanglement of epistemic and ethical uncertainty in Do Cs and other medical contexts, and how they interact to create both epistemic and ethical risks. Philosopher and bioethicist L. Syd M Johnson pulls together multiple threads in this work: the ontological mysteries of consciousness, medical uncertainty about unconsciousness, ableist bias, withdrawal of treatment in neurointensive care, and the rarely questioned view that consciousness is essential to personhood and moral status. Johnson challenges longstanding bioethical dogmas about Do C patients, and argues for an ethics of uncertainty for contexts where there is a need for decisive action in the presence of unavoidable uncertainty. The ethics of uncertainty refocuses ethical inquiry concerning persons with Do Cs, placing less emphasis on their contested personhood, and more on inductive risk and uncertainty, on respect for autonomy, and especially on epistemic justice. With applications to various decisional contexts where uncertainty and ethical risk interact, this ethical approach enables surrogate decision makers facing fraught and risky choices to fulfill their obligations as moral and epistemic agents.