Tuesday, 19 April 2011

Philosophy Lessons: Identity Through Time

When I talked with my philosopher last night about this entry last night, we thought at first that I would try to do a short summary of metaphysics, as in “everything in metaphysics.” That was a mistake. Hello, metaphysics has been around since at least Thales of Miletus (one of the Pre-Socratics).

So instead, we picked something from within metaphysics to talk about today. This is an analytic approach to the issue of identity. I am very open to doing a continental discussion of an issue within metaphysics if any of you would like to suggest something, but I need some direction because my knowledge of continental philosophy is limited to existentialism, literary theory, and a smidge of American Pragmatism (why I know something about AP is a weird story, so I won't go into it).

Anyway, today we will look at identity.

The Stanford Encyclopedia of Philosophy article on Identity[1] credits Irving Copi as defining the problem of identity through time with two statements:

1. If a changing thing really changes, there can't literally be one and the same thing before and after the change.
2. However, if there isn't literally one and the same thing before and after the change, then no thing has really undergone any change.

This is too technical, so let’s super-simplify these statements:

1. If a thing that can change really changes, it’s not the same thing it was before the change as it is after the change occurs.
2. However, if you have such a thing that is not the same thing before it changes and after it changes, then there isn’t really ONE THING that has changed (it is two separate things: (1) Thing 1: the thing before and (2) Thing 2: the thing after).

To simplify further, let’s look at some examples.

What happens to the same person over time, even if one’s body changes? What if you lose your memory or are involved in an accident that damages your brain and alters your personality? One of the most common examples that philosophers learn that looks at these questions is that of Phineas Gage.

You may have encountered Mr. Gage in a psychology class, because this example also pertains to behavioral studies. If you remember, Mr. Gage worked on the railroads in the mid-1800s as a foreman. He survived a terrible accident, in which an iron rod was driven through his head. This accident destroyed most of his brain’s left frontal lobe.

After the accident, Mr. Gage’s personality was completely changed.  His friends knew him before the accident as a naturally intelligent person, well-balanced, and a good business man. After the accident, they noted that he had become selfish, prone to profanity, and intellectually childlike.

This example seems to point to a person (a thing) that is a different person before an event (Thing 1) than they are after the event (Thing 2).

Another example that I like is from philosopher John Locke. In philosophy-world, the problem is referred to as “Locke’s Socks” (the best name EVER for a philosophy problem).

Locke has a favorite sock that happened to develop a hole in it one day. He wondered if the sock would still be the exact same sock if he was to apply a patch to this hole. If the answer was yes, it would be the same sock, then he wondered if it would be the same sock if there was another hole that required another patch. And then (extreme example time), what if the socks became gradually so holey and then patched to the extent that all of the old material from the original sock had been replaced with patches? Would this still be the same sock?

Also, are you exactly the same person that you were when you were five-years-old? Does this mean that the person you were at five is a completely different person than the person you are right now?

Practical Application: Questions you could ask your analytic metaphysician

1. Do you think that the Philosiologist’s super-simple explanation of the problem of identity through time is too simple? Is it missing certain important points?
2. Do you think examples like Locke’s Socks tell us anything important about the problem of identity?
3. Which philosophical figures do you align yourself with in this debate?
4. Are there any approaches that you feel are deeply mistaken in this debate?

This is a very simplistic look at the problem of identity. If you want more reading material on this subject, you might try the Stanford Encyclopedia of Philosophy entry on “Identity and Time” or the Wikipedia article on “Identity and Change.” Just a warning, the SEP article is muy technical for most of us, so beware!

~The Philosiologist~

[1] Gallois, Andre, "Identity Over Time", The Stanford Encyclopedia of Philosophy (Spring 2011 Edition), Edward N. Zalta (ed.), URL = <http://plato.stanford.edu/archives/spr2011/entries/identity-time/>.  

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  1. My metaphysics is not very good, but there's a problem in the example above.

    "1. If a changing thing really changes, there can't literally be one and the same thing before and after the change.
    2. However, if there isn't literally one and the same thing before and after the change, then no thing has really undergone any change."

    It's true if a changing thing really changes, there can't be the same thing. But there can still be one thing before and after the change if the thing after the change replaces the thing before the change. So there really is something that actually changes.

    Locke's sock is a lovely example, but I don't think it can be wholly applied to humans. Humans are far more complicated species than "socks". We are not exactly the same persons as we were when we were five years old because our personalities are open to modification and correction as experience accumulates yet we are still the same persons in the sense that we still have a sense of connectedness and continuity out of our memories and fragmented experiences that have constructed the self.


  2. Nicely done! So should we punish Roman Polanski for having sex with a 13 year old 30 years ago?

  3. In the early years of the twentieth century, A.J.Ayer, who was to become the Wykeham Professor of Logic at Oxford, made fun of silly continental philosophers like Heidegger who still thought that metaphysics was possible. One of Heidegger's books was called The Metaphysical Basis of Logic).

    By the end of the twentieth century, followers of Heidegger like Jacques Derrida proclaimed the end of metaphysics. Meanwhile, Ayer's successor, Michael Dummett, wrote a book called The Logical Basis of Metaphysics.

  4. William, the problem of identity is not one of personal identity. Identity, as it is known in metaphysics, is the notion of numerical identity, as in what resides on either side of the "=" in the formula "A=B". The problem of change is one of numerical identity.

    The issue of whether or not I am the same person (i.e., Roman Polanski) is a different question. The problem if numerical identity does not, usually, come to questions of moral responsibility, though the problem surrounding personal identity (whether i am the same person as me 10 years ago...or even last week) may have repercussions in questions of moral responsibility.

    Another way to put this: whether Agent X is morally responsible for action Y is not a metaphysical question. Whether X at time Y is numerically identical to Z at time Y1 is a metaphysical question.

    And don't get me started on lumps of clay and statues!

  5. I was surprised to see American Pragmatism labeled as "continental." I've always thought of the classical pragmatists -- with the possible exception of Dewey -- as early analytic philosophers. Moreover, later pragmatists (not all Americans) have been basically analytic philosophers -- Putnam, Price, Brandom -- with the possible exception of Rorty. And a bunch of close philosophical kin (pseudo-pragmatists?) -- like Ramsey, Wittgenstein, Carnap, and Quine -- are usually counted as analytic philosophers (or at least, they are on the analytic side of the analytic/continental split).

  6. By reading this I feel like I'm reading my behavior! But I am a non-philosopher!!! Have I chosen wrong my career (mathematician)?? Jaja, love your blog, my girlfriend is starting to understand me ;)

  7. Wholelaffer, I'm interested by your post but I'm not entirely sure I understand. Care to elaborate?

  8. Cole, on which point do you want elaboration on exactly? I would not want to get too far into the weeds as metaphysics and personal identity can get highly technical and broad.

  9. doesn't (post)structuralism, esp. its linguistic form, 'fix' this by defining things as a negative collection? that a thing is the only thing that it is not? derrida (vis a vis his precursors) claims to end metaphysics by getting rid of the "one thing" and giving the collection of things singularity only in language. [i know it continental not analytic, so take it for what its worth to the convo...]

  10. . . . and that is why most of us don't consider Derrida a philosopher. Nobody thinks that's intelligible, needless to say a "fix" to the problem of identity over time.

  11. Anonymous, I suggest an exchange between Derrida and John Searle related to Derrida's criticism of Austin's performative utterance notion, that is, the semantic aspect of certain linguistic forms that are like actions (promising, acting, hoping, etc) and cannot be seen as true or false but rather have a certain fit or not. Anyway, Derrida's essay is "Signature Event Context" and Searle's reply is " Reiterating the Differences - A reply to Derrida". Derrida replies in "Limited, Inc" in the Afterword.

    John Searle is a well-known analytic philosopher. I think he comes out in this exchange but my buddy disagrees. I can see his point.

  12. Cole, since I am not sure what you want me to elaborate on exactly, let me try another way to make the distinction: metaphysics is the study of what there is (put it logically, it is the domain of discourse over which one can quantify). A fundamental part of what there is are objects, like rocks, planets, black holes, cars, etc. A puzzle arises when one ties this simple notion with time: what relates one object and that very same object at a different time? How is a rock at one time the very same rock at another time (that is, how does "A at time T1 = B at time T2"). This is the notion of identity over time (a bit more complex then simply "A=B" the notion of identity but not indexed to time).

    On the morality question, the problem of identity or identity over time does not really enter into debates since we are talking metaphysically and whether or not an object exists over time (e.g., a rock) does not have a moral dimension.

    However, another notion is of PERSONAL identity: what relation(s) explain how a person is the very same person over time. Sounds similarly put, but the relation will obviously be much different then the relation between a rock at time1 vs. time2. This has a moral dimension because the notion of personal identity is required for a person to be morally responsible for a past action, for if there IS no relation between person1 at time1 who committed murder and a person2 at time2, then person2 is not morally responsible for the murder.

    Does that distinction make more sense? Even though the questions sound similar, there is a big difference in how objects might be related to one another and how persons are related at different times.

  13. To follow up on Jonathan's comment, the Classical American Philosophers are certainly not Continental in any strict sense. They aren't from the Continent! Neither are they Continental in any meaningful metaphorical sense. And while they influenced later analytic philosophers, it would be conceptually and temporally backwards to call them analytic philosophers.

    The short response is that not all philosophy boils down to this Continental-Analytic divide. I'm very glad to see so many newer philosophers trying to transcend it, because it's an increasingly tiresome and unproductive false dichotomy.

  14. For anyone delving a little deeper I recommend David Lewis' "argument from temporary intrinsics". This concerns the nub of the problem and features in a brief and exhillerating couple of pages in "On The Plurality of Worlds". Don't read it all, your head will break. Page 260ish from top of head.

    A popular and (I think!) modern solution is beautifully sketched in Ted Sider's "Four-Dimensionalism" (first chapter does the trick). Here he argues four a view of time such that it is exactly analogous with space's three dimensions. The problem of change is taken to be solved by talking of objects as 4D worms that trace a path through space-time (that is the combined block of space AND time). To say that someone is standing at time t and not standing at time t1 is just analysed as different object parts of a 4D whole. A bit like the untroubling fact that you are both touching and not touching the ground simultaneously (touching via feet-portion, not-touching via other-portions). Very physics-friendly answer that.

    I thought this was all rather lovely. But then I am one of the damned...


  15. I've seen this same problem, but the story is about a boat. Basically the boat leaves shore, during its journey all of the wood that makes up the boat is replaced over time. When the boat returns to shore, is it the same boat? My response is that the key to identity is function. For example, if the boards of the boat were laid in a pile in the lumber yard, the question of identity wouldn't hold. Yet, when those parts are connected in the proper manner, they function as a new whole. This function persists as long as the parts are in relation to one another in such a way as to maintain the same function.

  16. Kyle,

    What do you say to the usual follow-up story, then? Suppose that Theseus sets sail as the captain of a boat. His men mutiny and throw him overboard. For a long while afterward, he swims along behind the boat (he's a Greek hero, so he can do this sort of stuff). His crew take on board pieces of drift wood, which they fashion into pieces to replace old parts of the boat. They then throw away the old parts. Every time they throw away an old part, Theseus collects it and, eventually, he rebuilds his boat from all of the original parts. Which of the two boats is the one that Theseus set sail in?