Is John Perry’s argument for claiming that memory is not the source of personal identity justified?
Answer by Jürgen Lawrenz
As you might expect, this question has occupied thinkers for 2600 years already, starting with Pythagoras. But the thread that runs through them all, including Perry, is the conception of a fourfold aspect on the matter; and now it depends on the cultural predilection of thinkers in their intellectual habitat which of the four they consider the most important, i.e. body, soul, brain or memory.
Today we have the advantage on all pre-scientific eras in that we are in possession of some hard knowledge which is indispensable — not for a solution to the problem, but for an accurate description of the terms of a relevant discourse. In this context, the importance of memory has been growing over the others, especially in relation to AI, where brain and memories work in tandem, where bodies are interchangeable and soul an absentee. This is not directly portable into a human organic context, but helps to clarify the criteria.
Namely: That personal identity rests on a person’s conscious awareness of themselves as being continuously the same “mind and body” — over the whole length of their life, across temporary states of minimal consciousness (as in sleep) and even across anaesthetic and/or comatose episodes. This argument is not in danger from points of view which rely on purely hypothetical objections (such as brain transplants or implants). Rather, it is reinforced by the integration of the most varied types of memories in the one body, which fall broadly into two types: Those transmitted by the parents (e.g. instincts) and those collected from experience. It is in this respect that the role of the brain is widely overstressed. The brain is not a storage bin for all our memories; on the contrary, every organ in the body has memories autonomous to itself; and we add to them in our years of learning (e.g. social conventions and every kind of “how to”). This means that the brain by itself is not a candidate for a role as the custodian of a person’s selfhood, even though it is clearly the seat of our conscious awareness, intellect, imagination and inventiveness. But without the resources of memory, this awareness (not to mention our subconscious estate) would hardly reach higher than that of other large mammals.
So the answer to your question is unavoidably ambiguous. Perry is certainly justified in claiming that memory is not the one source of personal identity, but then neither is the brain nor the body, except that the latter is evidently the housing for this collective. Which apparently leaves the soul out in limbo, for whatever definition it has been given in the past, seems to have been a simplex concept for the complex concept insinuated by the above — the sort of thing styled “the ghost in the machine” by Gilbert Ryle. I’m not inclined to weigh in on this; but by the same token I see no need for positing soul as a separate faculty, when its capacity is analysed in virtually identical fashion to the body, brain and mind consortium. This is conceding that soul may possibly be the life force itself.
Yet Perry seems strongly inclined to include soul in his disquisitions (fitting the mise en scene of his dialogue at the bedside of a dying person — ‘A dialogue on personal identity and immortality’, 1978). But this is a highly debatable issue, as ‘soul’ is not an organ, nor a thing or common existent, therefore indiscernible to measurement. Therefore while his arguments are well-reasoned and persuasive, he cannot clinch the point and, in my opinion, does not mark an advancement on Aristotle, the Scholastics or Leibniz. (Nevertheless, it is rare enough for a philosopher to explore the gamut of issues involved in personal identity through the medium of a Platonic dialogue, which only goes to show what a wonderful genre it is for philosophical enquiry!).