 As noted, this entry will focus on human beings with “radical cognitive  disabilities”[2]  — disabilities in intellectual function and capacity that limit or preclude the development of one or more attributes believed to confer full moral status. Among those attributes are the consciousness of oneself as a temporally-extended being; practical rationality—the capacity to govern one’s actions by reasoning about how to act; and the capacity to make and respond to moral demands. (We will often abbreviate the list to “self-consciousness or practical rationality” without making any assumptions about the centrality or relationship of the two attributes.) These attributes, as well as others held to be required for full moral status, may be possessed by different subsets of human beings, and the relationship among such attributes is a matter of considerable dispute. This dispute, however, is best deferred to a fuller treatment of the grounds of moral status; we will discuss them only to the extent that they bear on the moral status of human beings with significant cognitive disabilities.