This is the first book to provide a sustained exploration of the philosophy of mistakes. Beginning with the distinction between mistakes and malfunction Kim Frost examines the idea that mistakes are a form of irrationality; whether there can be mistakes of sensation and emotion; the idea of mistakes as imperfect exercises of fallible powers; the seemingly paradoxical theory that mistakes seem accidental yet also explicable; and mistakes in the context of non-human animals, such as the Sphex wasp, human experience and taking responsibility for mistakes.