Neural prosthetics (neuroprostheses, neural prostheses) are devices or systems that influence the input and output of information in the brain. They modulate, bypass, supplement, or replace regions of the brain and its connections to the body that are damaged, dysfunctional, or lost from brain injury, congenital conditions, limb loss, or neurodegenerative disease. Neural prosthetics can generate, improve, or restore sensory, motor, and cognitive functions. Some prosthetics are implanted in the brain. Others are connected to it in brain–computer interfacing. This book describes auditory and visual prosthetics, deep brain and responsive neurostimulation, brain–computer interfaces, brain-to-brain interfaces, optogenetics, and memory prosthetics and discusses some of their neuroscientific and philosophical implications. The neuroscientific discussion focuses on how neural prosthetics can restore brain and bodily functions. The philosophical discussion focuses on how people with these prosthetics can benefit from or be harmed by them. It also focuses on how these devices and systems can lead to a better understanding of or change our attitudes about the brain–mind relation, identity, mental causation, and agency. The book considers the therapeutic, rehabilitative, and restorative potential of neural prosthetics in improving functional independence and quality of life for millions of people with disabling conditions.