Research Question
Is Memory a Necessary Condition or a Sufficient Condition for Personal Identity?
Stimulus
“Gage, a railroad employee, was in the wrong place at the wrong time, when an explosion sent a metal bar through his cheek and out the top of his head. The accident destroyed much of his prefrontal cortex, but, surprisingly, he survived and seemed not to have lost any of his intellectual abilities. However, in many other respects, Gage was a changed man. He was unable to plan the work he and his crew needed to accomplish and frequently spoke in a profane, rude, and irreverent manner, all counter to his preinjury personality.”
From Psychology (Seventh Edition)by Peter Gray and David F. Bjorklund
After the accident, Phineas Gage experienced a significant change in his personality and manners. The alteration was so extreme that his friends and acquaintances actually started to view him as “no longer Gage”. What made Gage become a so different person, even losing his own personal identity in his friends’ eyes? Although his physical body was mainly the same, his psychological characteristics had been significantly altered. But what characteristics were those? This leads us to the discussion of the problem of personal identity. Here, the problem of personal identity can be understood as what it takes for someone to remain the same person from one time to another. It is to ask what makes me the same person as that crying baby 17 years ago or that old man 70 years later. It is a question about persistence and what makes this persistence possible.
Philosophers have suggested various criteria for our personal identity, either physical or psychological. In this essay, I would mainly focus on the Memory Theory proposed by John Locke [1]. According to him, sameness of memory is metaphysically necessary and sufficient for sameness of person. However, I only agree with him partially. From my personal point of view, I would like to argue that memory is a necessary condition for our personal identity to persist as he suggests; however, it is not a sufficient condition.
In the chapter of An Essay on Human Understanding entitled “Of identity and diversity”, Locke suggests that “for as far as any intelligent being can repeat the idea of any past action with the same consciousness it had of it at first, and with the same consciousness it has of any present action; so far it is the same personal self.” [2] This explains why we refer to his theory as Memory Theory. For example, there is a person at t2. In order for him/her to be identical with the person at t1, the same elements of consciousness ought to be shared. That is to say, if the person at t2 can have the memory of doing event A at t1 (“repeat the idea of any past action with the same consciousness”), he is identical with the person at t1. And according to Locke, memory is both the necessary and sufficient condition for personal identity. I would like to further discuss about these two propositions in the following essay.
Is it really a necessary condition? If it is, then, it is to say that if one at t2 does not have memory for the time t1, he/she cannot be the identical with the person at t1. Thomas Reid actually applies this as a counter-argument against the Memory Theory [3]. Naturally, people forget about their past. Nobody has the ability to remember everything after born. If memory is really the necessary condition, the corollary follows that if I totally forget anything happened in 2014, I lost my personal identity at that time. Therefore, there should be a gap or disconnection existing. It is clearly against our intuition since our identity ought to be continuous. Furthermore, everyone experiences childhood amnesia, which means that one cannot have a clear memory before 2 or 3 years old. Nevertheless, personal identity must also sustain at that time, or we need to accept the fact that every baby is not the same person after 20 years.
This is one of the most common rebuttal against Memory Theory. Nevertheless, I think this rebuttal is actually based on a too simplistic understanding or even misunderstanding towards Locke’s theory. Naturally, we do lose our memories or consciousness (e.g. when we forget something or when we are sleeping). But Locke would possibly suggest that, as long as we still have the psychological continuity with a past self, by a past memory, our personal identity is still persisted. Taking the example previously, if one at t3 has the memory of doing event A at t1but loses the memory at t2, there is still a continuity existing between t1and t3. There is a lot overlapping and a causal relationship between them. As long as this is fulfilled, Locke would still suggest the maintenance of personal identity in between these two time points. Therefore, I am still defending Locke’s theory at this point.
Then, what about total amnesia? Intuitively, if one loses all of his past memories, he/she loses his personal identity as well. By analogy, he/she just becomes a “rooted machine”, like a new born baby in this world, a tabula rasa. However, someone may still argue that, even if one forgets about his past, forget all of his episodic memories and experiences in the past, as long as his personality, behavioral patterns and preferences do not change, his personal identity is not lost. Therefore, they conclude that memory is not a necessary condition for personal identity. But, one question worth asking is whether this is on earth possible or not.
Before answering the question, we need to make a distinction between different kinds of memories in order to clarify our discussion. There are explicit memories which can be explicitly expressed using language and implicit memories which cannot. For example, episodic memories for our past experiences and semantic memories for our knowledge and language are all part of the explicit memories. For implicit memories, they may include memories formed within our unconsciousness or from priming, which may be crucial for our preferences and interests.
Therefore, in defend of Memory Theory, I would say it is impossible for one to keep his personality, behavioral patterns or preferences after total amnesia since these psychological characteristics all depend on our memories. For instance, our preferences may depend on our episodic memories and implicit memories. Our habit of language use may somewhat rely on our semantic memories. To conclude, if we lose all those memories, it is definitely impossible for these psychological characteristics to remain intact. They must suffer from extreme changes and, therefore, lead to a loss of personal identity.
All in all, through the previous discussions, we can confidently reach the conclusion that memory is necessary for our personal identity. By responding to the existing rebuttal and further suggesting the case of total amnesia, the significant role that memory plays in making our personal identity possible is manifest and undeniable.
Is it a sufficient condition then? If, as suggested, the person at t2 has the memory of experiencing an event at t1, does it necessarily prove that the person at t1 is identical with the person at t2? I would answer no.
My argument will be mainly related to fake memory or quasi-memory. Our memories of the past, instead of being experiencing the past again, are actually reconstructions from the present. That is to say, they are merely experiences recreated at present, based on certain information and clues we possess. But why does this matter to our discussion about memory and personal identity? Because it actually suggests the possibility of having false or fake memory.
Consider the following case, which is from a psychology study aimed to show the vulnerability of our memories [4]: you remember that when you were a child, your parents once brought you to Disneyland and had great fun. You “recall wonderful earlier experiences at Disneyland, such as singing It’s a Small World After All, running from ride to ride, and shaking hands with Bugs Bunny”. Everything is so vivid and you are very certain that you have experienced these in the past. However, there is one mistake in your memory. Bugs Bunny is a character of Warner Bros., not of Disneyland. Therefore, it is impossible for you to have this kind of experience in your childhood. This memory is fake to some extent. If we really follow Locke’s Memory Theory, we would say that, since you have the memory at that time, the person at that time is identical with you. However, it is intuitively bothering since these things even have not ever happened. How can we say that there is a person identical with you at that time?
Another thought experiment involves memory transfer. Imagine there is person A and person B. They are strangers to each other and they have no common experience or memory in the past. Now, a doctor secretly transfers part of person B’s memory into person A, without anyone noticing this transference. Furthermore, after this transference, since all of these memories are from a first-person perspective, person A takes the memory transferred from person B as his own memory, without any strange feelings or disconnectedness. Then, if we again follow Locke’s theory, we will encounter the same problem suggested previously: if you did not even really have that experience and been that place in the past, how can you be identical with that actually non-existent person? This is very contradictory. But, for the present you, you still persist your identity since, if you make a connection with the previous example of person at t3 forgets about t2 but remembers t1, there is still a continuity throughout time. Even though there may be disconnectedness or false memories in between, as long as the continuity of the previous you still exist, your identity is remained.
Then, what if the doctor transfers B’s memory totally? What if all of A’s original memory is supplanted by B’s memory, also without anyone noticing? In this case, although the whole memory is continuous, we would still intuitively recognize A as no longer A, since he/she actually becomes a copy or clone of B. There are differences between them physically definitely. But for their mental world, I would suggest that they become almost completely the same. Since there are both natural and experiential influences on our psychological characteristics, the natural tendencies or predispositions may still be different. However, since their memories become exactly the same, it is reasonable to accept the previous view. Therefore, again, it seems that memory cannot be a sufficient condition for our personal identity.
Finally, if we return to the case of Phineas Gage, we will recognize it as also suggesting that memory cannot be a sufficient condition for identity. Since Phineas Gage’s memories for his past were all remained intact, memory was definitely not the factor. The reason for why his friends started to view him as “no longer Gage” was actually the changes in his other psychological characteristics, including his personality, use of language and other manners. Therefore, only having the memories does not guarantee the personal identity to remain intact.
As a result, I think we have strong reasons to state that memory is not a sufficient condition for personal identity as well.
To conclude, although Locke argues that memory is both the necessary and sufficient condition for personal identity, in this essay, I reject his idea partially and propose that it is actually not sufficient. That is to say, if we remain our personal identity, we must remain our memories, at least partially, as well; however, if we have our memory, it does not necessarily prove the persistence of personal identity. For the problem of personal identity, I think we still need to further discuss about numerous other criteria. After all, what exactly makes the persistence of our personal identities possible is still mysterious and worthwhile discussing about.
[1]John Locke. “On Identity and Diversity.” In An Essay Concerning Human Understanding. (Oxford University Press, 1975).
[2]John Locke. “On Identity and Diversity.” In An Essay Concerning Human Understanding. (Oxford University Press, 1975).
[3]Copenhaver, Rebecca. “Reid on Memory and Personal Identity.” Stanford Encyclopedia of Philosophy, Stanford University, 18 Mar. 2009, plato.stanford.edu/entries/reid-memory-identity/#ObjLocPerIde.
[4]Braun, Kathryn A., et al. “Make my memory: How advertising can change our memories of the past.” Psychology and Marketing, vol. 19, no. 1, 2001, pp. 1–23., doi:10.1002/mar.1000.
Bibliography
Books
Gray, Peter, and David F. Bjorklund. Psychology. Seventh ed., Worth, 2014.
Locke, J., 1690, Essay Concerning Human Understanding, P.H. Nidditch (ed.), Oxford: Oxford University Press, 1975.
Websites
Copenhaver, Rebecca. “Reid on Memory and Personal Identity.” Stanford Encyclopedia of Philosophy, Stanford University, 18 Mar. 2009, Retrieved from https://plato.stanford.edu/entries/reid-memory-identity/#ObjLocPerIde.
Journals
Braun, Kathryn A., et al. “Make my memory: How advertising can change our memories of the past.” Psychology and Marketing, vol. 19, no. 1, 2001, pp. 1–23., doi:10.1002/mar.1000.