Degrees of personhood

In this paper I argue that a Naturalist conception of personhood, such as the one defended by Derek Parfit, implies that there are degrees of personhood, i.e., that it makes sense to say one individual has a greater degree of personhood than another. I describe both criteria of general personhood, which distinguish between persons and non-persons, and criteria of particular personhood, which distinguish between one person and another. I examine some of the consequences for ethics, including the rights to life, self-determination, and treatment. There may be circumstances in medicine where we have to judge the value of a patient's life in order to decide what medical treatment, if any, to provide, and although it may be emotionally difficult and politically dangerous, one relevant factor is what degree of personhood that individual has.