Amy Kindof memories between two individuals for them to count as the same person we can instead
require simply that there be a continuity of memory between them. It doesn’t matter, then, that
the retired old man can’t directly extend his consciousness backward to the experiences of the
young thief. Since he can extend his consciousness backward to the experiences of the brave
officer, who in turn can extend his consciousness backward to the experiences of the young boy,
the experiences of all three stages are part of the same shared continuity of consciousness. Let’s
call this the continuity of consciousness view.
While the continuity of consciousness view avoids the problem posed by the Brave Officer
case, views in the Lockean spirit face another objection that cannot be dealt with so easily. The
Brave Officer problem arises essentially due to cases of forgetting.^2 But in addition to the fact
that some of our memories can be forgotten, there is also the fact that some of our memories
can be false. When I extend my consciousness backward to some event, I take that to be an event
that I myself experienced. But what if I’m wrong?
Cases of mistaken memories are not at all uncommon. Consider this scenario: Jordan starts
recounting a story about a time he beat up a bully who was taunting a group of younger kids.
In fact, his brother Zach was the one who pummeled the bully. (“Hey, that wasn’t you, that was
me!” he might say.) Of course, this might just be a case of boastfulness on Jordan’s part. But it
also might be a case where he sincerely believes that he was the one to deliver those punches.
From the inside, his apparent memory of doing so seems the same as all his genuine memories.
But we don’t want to take this apparent memory to imply that Jordan is identical to the person
who beat up the bully. False memories cannot make you into someone that you’re not.
It may seem that there is an easy fix here. Why not simply require that the continuity of con-
sciousness be real rather than apparent? Unfortunately, however, things are not quite so simple.
As pointed out by the 18th-century philosopher and theologian Bishop Joseph Butler (1736),
views in the Lockean tradition run into a problem of circularity. We are trying to use the notion
of memory to explicate personal identity. But, as we have seen, doing so will only be plausible if
the memory in question is genuine and not merely apparent. So how are we going to distinguish
those cases in which memories are merely apparent from those in which they are genuine?
Going back to the case of Jordan and Zach, it seems natural to say something like this: Since
Zach was the person who pummeled the bully, his memory is real, and since Jordan wasn’t the
person who pummeled the bully, his memory is merely apparent. Now look what’s happened:
To explain personal identity, we’ve invoked continuity of memory. But to explain continuity of
memory, we’ve invoked personal identity. As Butler put it, we can’t define personal identity in
terms of memory if it turns out that a proper understanding of memory presupposes the notion
of personal identity.
Philosophers in the Lockean tradition have made various attempts to solve this problem. One
particularly promising line of defense invokes a causal theory of memory. On this kind of theory,
there must be an appropriate causal connection between a mental state and an experience in
order for the mental state to count as a genuine memory of that experience (see Perry 1975 for
discussion). Perhaps this defense is successful, perhaps not. But even if it is, there is yet one more
problem facing the continuity of consciousness view that we need now to consider, namely,
what’s often known as the problem of reduplication.
To motivate the problem, it will be helpful to return to the example we saw above of con-
sciousness transfer. Recall that in the movie Avatar, Sully’s consciousness is transferred from his
human body to a Na’vi body. But now we might wonder: once his consciousness is transferred
out of his original body, why can’t it be transferred back into two or more bodies? As Reid
noted in the 18th century, “if the same consciousness can be transferred from one intelligent
being to another ... then two or twenty intelligent beings may be the same person” (Reid 1785: 114).^3