 Why are cognitive disability and moral status thought to be sufficiently connected to warrant a separate entry? The reason is that individuals with cognitive disabilities have served as test cases in debates about the moral relevance of possessing such intellectual attributes as self-consciousness and practical rationality. If a significant portion of human beings lacks self-consciousness and practical rationality, then those attributes cannot by themselves distinguish the way we treat cognitively developed human beings from the way we treat non-human animals and human fetuses. If we cannot experiment on or kill human beings who lack those attributes, then the lack of those attributes alone cannot be what justifies animal experimentation or abortion.