Derek Parfit - Criticism of Personal Identity View

Criticism of Personal Identity View

Fellow reductionist Mark Johnston of Princeton rejects Parfit's constitutive notion of identity with what he calls an "Argument from Above". Johnston maintains, "Even if the lower-level facts do not in themselves matter, the higher-level fact may matter. If it does, the lower-level facts will have derived significance. They will matter, not in themselves, but because they constitute the higher level fact."

In this, Johnston moves to preserve the significance of personhood. Parfit's explanation is that it is not personhood itself that matters, but rather the facts in which personhood consists that provide it with significance. To illustrate this difference between himself and Johnston, Parfit makes use of an example of a brain-damaged patient who becomes irreversibly unconscious. The patient is certainly still alive even though that fact is separate from the fact that his heart is still beating and other organs are still functioning. But the fact that the patient is alive is not an independent or separately obtaining fact. The patient's being alive, even though irreversibly unconscious, simply consists in the other facts. Parfit explains that from this so-called "Argument from Below" we can arbitrate the value of the heart and other organs still working without having to assign them derived significance, as Johnston's perspective would dictate.