I mean to say I’m not essentially a person. Let’s say someone is a person if and only if he possesses self-awareness, consciousness, rationality, the ability to communicate, and so on. Call that the standard view. The standard view is found in Singer, Glover, Tooley, Lowe, Williams, McMahan, and Parfit and goes at least as far back as Locke. According to the standard view, the property of being a person confers a special moral status on those who instantiate it. Only persons have the full profile of moral rights, so their lives have a moral protection that is not afforded to non-persons.
I deny the standard view, since we (we normal adult humans, if you insist) have rights and none of us are persons. Suppose for reductio that I am a person essentially. I have essentially the properties of consciousness, self-awareness, rationality, ability to communicate, etc. The predicates describing a person are, of course, vague. There are borderline cases of rationality, self-awareness, consciousness, and the ability to communicate. Alzheimer’s disease, among other debilitating diseases, might cause me to be indeterminately rational, conscious and self-aware. If I am indeterminately rational, conscious and self-aware, then I am indeterminately a person. It’s possible that there are indeterminate persons (given the standard view), but it’s *not possible that I indeterminately exist*. There exist things that are indeterminately persons, but there can exist nothing, persons or otherwise, that have the property of indeterminately existing. Since I am a person essentially, I determinately exist only if I am determinately a person. But I am an indeterminate person. Therefore, I indeterminately exist. That’s impossible. That concludes the reductio. I cannot be a person essentially.
Objection: You can be a person essentially without that entailing that you indeterminately exist. Instead, you should conclude that you cease to exist if the person-defining properties you instantiate become indeterminate.
Reply: True. But then being a person does not provide me with any moral protection. If you cause me to become borderline rational, you kill me. But you do not thereby violate my right to life.
Suppose I’m a person contingently. The psychological traits and capacities standardly attributed to persons are not traits and capacities essential to my continued existence. I am a person, so there is a person standing before you, but I might cease to exist without any person ceasing to exist. The persistence conditions for the person standing before you are not the persistence conditions for me. My persistence need not consist in any psychological continuity at all. Suppose my continuity conditions are purely somatic. I might be identical to my brain or a sufficiently large part of my brain. On the standard view, what matters morally is that the person standing before you not be killed. Suppose you place me in a device that replaces all of my brain cells with silicon-based cell-like replicas, but preserves all of the relevant psychological continuity including consciousness, self-awareness, rationality and so on. I would cease to exist but the person standing before you would not cease to exist. You would have killed me, but you would not have killed any person. The same person would be instantiated in another body. And since you did not take the life of any person, you would not have violated any person’s rights. If I am a person contingently, then I have no moral right against you that you not kill me. You may kill me just for fun, if you’d like, so long as you do not kill any persons.