Personal Identity (Fall 1999) / Notes / Two challenges to the Further Fact View

Two challenges to the Further Fact View

2-4 November

The main point

Parfit poses two challenges to what he calls the Further Fact View. This is the view that questions about personal identity must have determinate answers; according to this view, there is always a fact about whether A is the same person as B. It is a "further" fact in the sense that it is thought to be a fact in addition to facts about bodily or psychological continuity.

The first challenge is posed by spectrum cases. No matter what view you take of what personal identity consists in, it seems that there can be a spectrum in which there are indeterminate answers to questions of personal identity. If you believe some psychological account, you will think there are indeterminate cases in the psychological spectrum. If you believe a bodily account, you will think there are indeterminate cases in the physical spectrum. Even if you aren't especially pulled to either of these philosophical positions, you'll think that there are indeterminate cases in the Combined Spectrum.

The second challenge is posed by fission cases. These seem to show that a person can survive into the future even though no one in the future is identical with that person. If I survive on Tuesday, who I am identical with on Tuesday?


It's not obvious whether fission cases should be described as cases in which personal identity questions have no determinate answers. On the one hand, it seems pretty obvious that I can't be identical with both of my fission products, so, one might conclude, there is a determinate answer to the question "is either of the resulting persons identical with me?" The answer is no (See Parfit, p. 264, for example). On the other hand, these seem to be cases in which there is a sense in which they are me (I survive, after all) but a sense in which they are not (no one is me, I'm not the same person as anyone). That seems like a case in which it's appropriate to say that the personal identity question has an indeterminate answer. (See Parfit p. 260, for example). I think both answers makes sense, but tend to adopt the latter for myself.

The persistence of the further fact

I think it's pretty clear why Parfit thinks the example of fission involves a "double success."

But why do I resist? I think that there must be a further fact of personal identity and my inability to find one in this case leaves me confused: because I believe in the further fact, I don't know how to describe what happens in a case like this one.

Here's why the idea that there is a further fact of personal identity has a grip on me.

Suppose I want to live into the future. What do I want? Minimally, I want this: I want it to be the case that I can look out the window and see the trees. If there is a time in the future in which that is true (I can look out ... etc.) then I will exist at that time. In order for that to be true, someone in the future must be me. But in the division case, none of the resulting persons is me. So I have a hard time understanding how I could survive division.

Here that is again.

(1) I will exist at a point in the future if and only if I will be capable of having experiences at that point in time. I want to be able to see the trees outside the window.


"Capable of having experiences" means I can have experiences such as looking out the window and seeing the trees. I say "capable" because I want to accommodate the possibility of sleep (without my death, of course: I exist while asleep).

(2) If I am capable of having experiences at a point in time, then (a) there must a person who is capable of having experiences at that time and (b) that person is me.

Can anyone deny that? It seems so obvious.

But it also seems that we have to give it up. In Parfit's division example, neither of the resulting persons is me.

At the risk of repetition, I give you once again:

Parfit's koan: I can survive into the future even if no one in the future is me.

According to Parfit, that's what we learn from this division example.

Those of us who bullishly believe in the further fact of personal identity don't think we learned anything. We're confused and unable to say exactly what happens in the division example. We follow Parfit's example. But we get hung up because we still hang on to this thought: I can't survive on Thursday if no one is the same person as me on Thursday. I can't survive if no one is me.

Parfit's challenge

Parfit challenges me to say what "that person is me" would involve beyond the facts about my physical and psychological relationships with a person in the future. The challenge is to say what such a further fact is and why I think it's so important. You could express this challenge in at least three, roughly equivalent, ways.

Once we know all the facts about how a future person is physically and psychologically related to me, what would we gain by knowing whether that person is the same person as me or not?

What would that additional thing, "being me," involve? What more do I want, beyond having certain physical and/or psychological relations with a future person?

I think I'd survive with a single hemisphere: I think I'd wake up and be able to look out the window and see the trees if one hemisphere were transplanted into another body. So why do I think something's missing when I have two transplanted hemispheres?

Furthermore, can I say what it is that I'm looking for? It isn't a separately existing entity or soul. We secular thinkers have given up on those. Anyway, I bought Locke's point a long time ago: we don't care about separately existing entities or souls. For all I know, I've had fifty or sixty separately existing entities during my life: would it make any difference if I found out that was true? (Maybe I should reconsider. Swinburne thinks so.)

Why wasn't the thing I want there in the Combined Spectrum, so that I could give determinate answers to questions about my identity at every stage of the Combined Spectrum, or, at least, had some confidence that there must be answers?

Can I meet the challenge?

Not to my own satisfaction. I'm caught and unsure how to escape.

I think that surviving into the future requires that I am identical with some person in the future.

But I also think I would survive the kind of division Parfit describes and I don't think I would be identical with either of the transplants.

On the positive side, I think I'm doing an adequate job of characterizing the further fact and thus explaining what "being me" would involve. A person's being me would involve my experiencing the world through that person's eyes (and other senses).

I think that's a further fact because it can't be a matter of degree whether I experience the world through a person's eyes or not: it can't be a matter of degree whether I feel that person's sharp, unrelenting pain. And I can't experience the world through two people's eyes at the same time. So, I think that for any person existing at any time, there must be a determinate fact: is the person me or not?

Persons and personal identity

David suggested that where this is going wrong is that Reductionism treats a person as a clump of psychological features. That will never explain what a person is or why persons are valuable.

We've seen part of this argumentative strategy before: see the last paragraph on the page Williams's experiment. There is a tendency for the conditions of personal identity over time to converge with the qualities that make persons valuable. Despite the fact that these two things don't seem to be linked in any obvious way, we often try to link them. It's possible that this is significant: what our repeated attempts to link these things might show is that there is a deep link between them that we can't see.

A separate set of questions raised by this concerns the extent to which our understanding of what a person is can be separated from our understanding of the necessary and sufficient conditions of personal identity over time. This is a fascinating topic; there are no obvious answers.

Here are some considerations. First, our account of personal identity over time should not be incompatible with our understanding of what a person is: the conditions on personal identity over time can't be conditions that no person could meet, it can't be possible to remain the same person over time despite ceasing to be a person, and so on. So far, so good.

Second, we should note that all of the things we've been talking about as candidates for what personal identity over time consists in are things that are shared by many animals that are not persons. My cat has memories and, certainly, a body.

Third, one might believe that these two issues are necessarily wrapped up since persons necessarily exist over time: there's no such thing as a momentary person. I believe this is a point that Marya Schechtman insists on in her interesting book The Constitution of Selves (Ithaca: Cornell University Press, 1996). (She teaches at the University of Illinois, Chicago, by the way: just up the road!)

Fission and the bodily criterion

You might recall that Williams tackles the problem of fission in "Personal Identity and Individuation." He tries to distinguish the kind of splitting that physical entities can undergo from the alleged reduplication that psychological continuity permits.

I think that what he has to say is very interesting, but that it ultimately fails to defeat Parfit's point (it was written before Parfit had started working on this problem). I'll post a short summary of the argument and my opinion on the next page: Physical and psychological fission.

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