Philosophy Ph.D. Dissertations


Capacities and Moral Status

Date of Award


Document Type


Degree Name

Doctor of Philosophy (Ph.D.)



First Advisor

R. G. Frey


The thesis of this essay is that, because human organisms have the specific sorts of capacities that they do, they have the sort of moral status (which I call “serious” moral status) that includes, as one of its components, a strong moral presumption against being killed. The main argument of this essay has three steps: if an entity is human, it has a set of typical human capacities; if an entity has a set of typical human capacities, it has serious moral status; therefore, if an entity is human, it has serious moral status. Typical human capacities include both “active” capacities and “passive” capacities, and also include both “lower-order” capacities and “higher-order” capacities. Although both distinctions are somewhat rough, I have an active capacity to raise my arm on purpose, a passive capacity to feel pain when pricked, lower-order capacities to do both of these things right now, and higher-order capacities to obtain these lower-order capacities when asleep, anesthetized, or temporarily comatose. Whereas most writers who focus on the moral relevance of capacities tend to ignore an entity’s higher-order capacities, or its passive capacities, or both, I argue that an entity’s passive higher-order capacities are relevant to its moral status. The five chapters of this essay are structured as follows. Chapter One explains the concepts of the main argument in more detail, and explains why personal pronouns such as “you” and personal names such as “Ronald Reagan” are applied to human organisms throughout the essay. Chapters Two and Three defend the first and second premises of the main argument, by focusing on human organisms who undergo temporary changes involving “incapacitation” of one sort or another. Chapters Four and Five relate the main argument to two controversial arguments in contemporary applied ethics: the Argument From Potential, which focuses on normal human organisms at the beginning stages of life (such as human infants, fetuses, and embryos), and the Argument From Marginal Cases, which focuses on abnormal human organisms (such as human organisms that are disabled, diseased, or genetically deficient in some way).