Epistemology for Time-Travelers

Epistemology for Time-Travelers February 2, 2012

I’ve been mulling over a weird thought-experiment, and I’d be really interested in your intuitions.  (I’ll explain why I’ve been thinking about it in a subsequent post).

Poof! In a burst of special effects, you’re confronted by a doppleganger you!

“Hi,” other!you says, “I’m you from the future.”  Future!you knows enough about you that you’re convinced it is indeed you, and does something that makes it probably s/he is really from the future (predicts a couple events).

“Wow,” you say, “my mind has been blown.”

“You shouldn’t speak so fast,” says future!you.  “I should tell you I’ve also converted to [not your current religious beliefs].”

After reviving you with smelling salts from the future, the new you says, “Look, I can’t tell you the exact reasons I changed my mind (it’s a timey-wimey restriction) but I’m glad to talk epistemology with you until you agree that we have the same threshold for evidence on this question.”

Should knowing that future!you has been persuaded be enough to persuade you?

Does the very fact of a conversion eliminate your confidence in future!you’s rationality?   What kind of things would you still have to agree on in order to believe that what persuades them would persuade you?

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  • Ben L

    Almost everyone and probably me as well starts fishing for reasons the status quo is true when confronted with evidence to the contrary, esp. about religion. I’d probably start asking if future!me had been hit in the head, if I would shortly be assassinated for being an atheist, etc. Future!me saying I am eventually converted is not persuasive, since future!me isn’t the same as whatever evidence actually converted future!me, and I haven’t seen that evidence. While future!me’s word might be the strongest possible endorsement, I would not change my beliefs at this time on one persons say so, without evidence. My guess is one of the things we would have to agree on would be what miracles would actually be evidence. Giant writing in the sky? Everyone hearing the same voice at the same time? Etc. How would you distinguish between aliens and god? etc.

  • Quid est veritas

    Q. What kind of things would you still have to agree on in order to believe that what persuades them would persuade you?
    A. Future!you will still agree with you about what “counts” as persuasive evidence for (whatever beliefs future!you holds) and will be able to use your thought processes to persuade you, won’t she?

  • Daniel A. Duran

    My current self is a forgetful mess that cannot remember where he parked the car, where he put the keys, forgets to wash the dishes and often forgets to eat. chances are my future self will be the same…why would I trust the expertise of that guy?

    But more seriously, his conversion would not force me to accept his views. His arguments might be subtler and more forceful than my own but he willingly decided to assent to those arguments and others that cannot be proved by reason.
    You can give an argument to someone but that person must be receptive to them and willing to accept them. Frankly, I sense that at the end of the day belief and unbelief are just the result of one’s volition and placing faith in some unprovable propositions.

    Would I be changed by my future self at the end of the day? dunno, but I will certainly ask him if he has seen my keys.

  • JenniferT

    Alas, there is a history of senility in my family so it wouldn’t surprise me as much as you imagine. I’d just be disappointed at not avoiding it. I consider the possibility of a rational conversion to be so remote as to be a non-starter.

  • This one of the most interesting questions I came across this year. Thank you. I have no answer though.

  • Noah Kristula-Green

    This reminds me of an answer that Christopher Hitchens gave when he was asked about the possibility of experiencing a death-bed conversion:
    “I can’t say that the entity (that by then wouldn’t be me) wouldn’t do such a pathetic thing, but I can tell you that, not while I’m lucid, no. I can be quite sure of that.”
    Video here, key quote at the end of the interview.

    So since Future!Me can’t tell me exactly why he has changed his views, I conclude there are a couple of possible reasons for this:
    1. He genuinely believes this stuff but can’t tell me what exactly got him to switch.
    2. He doesn’t actually believe it but has out of convenience or because of some other regime he lives under in the future has to, and can’t tell me that because of the timey-wimey restrictions. (He is not allowed to say “In the future, Robo-Pope didn’t give Jews too many options.)

    So as long as the timey-wimey restrictions prevent him from telling me what got him to change, it’s going to be a very short conversation.

    “Does the very fact of a conversion eliminate your confidence in future!you’s rationality?”
    -Throws into doubt, but leaves open the possibility for a rational reason.

    And it’s honestly hard to see myself being convinced of anything without breaking the Timey-Wimey stuff.

  • Hibernia86

    The only thing that matters is evidence. It would be arrogant of me to say “Well, future me accepts this idea so since it is me accepting it, it must be true.” I shouldn’t have so much hubris as to think that if I believe it therefore it is obviously true.

    • Patrick

      The key is to not question the hypothetical.

      If you stipulate that there exists evidence that meets your requirements for concluding that [X] is true, then given that stipulation, it would be irrational to think that [X] isn’t true. It doesn’t matter that you don’t actually know the evidence.

      That’s what all the time travel stuff is supposed to be doing in the little story above.

  • Darric

    I would be inherently suspicious as future me would know that him coming to tell me I had converted would not be enough evidence to make me convert. So why in the hell had he come back. If it was to tell me that he converted in order to convince me to convert when he knows I wouldn’t then that simply tells me that he is not me because I would never do that.

    If he had come back for another reason and the conversion was an unrelated matter I would assume that I was likely to suffer some sort of accident or mental breakdown in the future.

    I would imagine most people in this situation would also question why they could come back in time and inform their past selves that they had converted but not inform them as to why. Saying “I can’t tell you the exact reasons I changed my mind (it’s a timey-wimey restriction)” would not be good enough for me.

  • Like most people here I first think of questioning the hypothetical. But I want to answer the actual question so I’ll assume the least convenient possible world and note that this includes several assumptions I’m not talking about right now.

    If the belief wasn’t intimately entangled with morals and relationships, future!Gilbert’s judgment would suffice to convince me. If he, for example, had decided homeopathy worked I would have to take that bullet.

    But it would be more complicated if he had disowned my family because he had decided they were all philosophical zombies. A radical change in religious beliefs would fall into the same category. In this case I wouldn’t only need reassurance he still shared my epistemological standards I would also need reassurance he still shared my morals. It is fully in my power to turn much more evil than I now am. And even now I have to be careful not to buy the elaborate rationalizations for my own evil I easily come up with. It wouldn’t help if future!Gilbert believed that wasn’t the problem, because evil!future!Gilbert probably wouldn’t consider himself evil either. So I think future!Gilbert would also have to convince me that I would judge my future sins irrelevant to his belief formation if I knew them all.

    Now if whatever brought him here also cloned me and clone!Gilbert would later accompany future!Gilbert to the future so that the timey-wimey restriction doesn’t apply to clone!Gilbert then my intuition says future!Gilbert convincing clone!Gilbert should suffice to convince me.

  • The first question I would ask is, “why bother returning to tell me this?”

    The past I had, which is very different from the present I am living, contains moments I am not proud of. Every time I have thought about should I have the option to go back & make a difference, would I? I always land in same place: The me I am now, is based on the me I was. If I went back, & provided me with information I didn’t have then, then I may well not turn out to be the person I am now, & despite life not being perfect, I’m happy with where I am now. I would thus assume that future me has made some bad decisions which have put him in position where he wasn’t happy with who he was. This would make me question whether the conversion has something to do with this possible state of dissatisfaction. This in turn would make me doubt that it was a good thing, & I’d rather not even waste my time engaging in the conversation, & deal with the problem when I get there.

    Since future me would know all this, I arrive at the question at the top. I (both me now, & me then) would know I’m too stubborn to listen, so why bother? Which would make me doubt it was indeed a future me.

  • keddaw

    “Hi,” other!you says, “I’m you from the future.”

    If you really were ever me then you’ll know that I think that since you have had many experiences I haven’t and have thought processes (soon to be shown to be wildly) different from mine, then you’ll know that I fundamentally cannot accept that you are, in any meaningful way, me.

    Now we’ve established that I will listen to you as I would anyone else that has shared experiences with me and I respect…

  • emily

    Honestly, I’ve always hated thought experiments because I find it hard to imagine what I would do or think in a realistic way when the very premises of the situation are unrealistic. So…I’m not sure.

    But since I’m not an atheist, I can say that rationality is not the primary reason for my current religious beliefs, so it would not take much for my future self to be “more rational;” it would, however, take some convincing for my future self to persuade me that it would be good to become “more rational.” But I am more likely to be persuaded by experience and feeling in the course of life and passage of time than one conversation, so I don’t think my future self could accomplish it in one conversation, although such a crazy circumstance could plant seeds of doubt, perhaps.

    Of course, it’s even messier to think about how the mere experience of meeting my future self matches or mismatches my religious beliefs – would that on its own be a source of doubt or conversion? That’s an interesting question. Not sure of the answer.

  • This reminds me of the post on this blog some years back about worrying whether one would remain moral in the future. This isn’t the sort of existential angst that Sartre talked about, which had to do with suicide, but it’s a parallel concern: what if I make an irreversible leap in the future which makes me someone I would currently loathe?

    If this were to happen to me, I would become incredibly uncomfortable generally speaking. However, I would not be surprised necessarily, since I tend to find many worldviews plausible and appealing. I would not be convinced, however, and while I would worry a lot about it I would not conclude that converting (now) is necessary (in fact, I would speculate that such news would change the space-time continuum, since I am now forewarned that I might be tempted to apostasy and therefore be guarded against it in the name, as a previous commenter put it, of status quo). However, this is indicative of a particular metaposition I have started to hold, which is that if atheism/ agnosticism/ Buddhism/ Taoism is true, it’s not particularly important that I believe in it. I’m sure people will disagree with me on this, but considering that I don’t think Christianity is an irredeemably destructive force, I hope you can understand that I wouldn’t think it’s morally urgent that I leave it even in the face of doubt (indeed, it’s not like I don’t have doubts now).

    Now, if future!me has converted to Islam or theistic Satanism or something else which would make conversion morally urgent because belief is itself now a moral issue, I would have to consider this more carefully. Like Gilbert above, I would need to ascertain that future!me still has the same basic moral orientation (which I would be trying to ascertain anyway). I would also need to ascertain that future!me wasn’t generally fuzzy-headed OR too certain in his (or her, in the case of a completely unexpected gender-change) epistemology. (I think a lot of errors in thought come from intellectual hubris.)

    This is getting too long for my liking, so one last thought: I do not share the bulk of the previous commenters’ refusal to believe that future!me could convert without some sort of head trauma or other neurological degeneration. Frankly, I find that sort of response indicates a slight blindness to both the legitimacy of other possible views and to the degree to which we all have biographical reasons for our current beliefs. An accretion of more biography could produce unexpected changes (has no one else experienced paradigm shifts or something analogous in thought?). But maybe I’m showing my own biography overmuch here; I am a Christian who has frequently flirted with rational materialism, and while that’s not a path I would expect going down again (if I were to become an atheist, it would be more like a postmodernist one, though not in the sense that I see this term used on this blog), I see enough of its appeal that I wouldn’t be shocked to find that future!me had done so.

  • Alex

    Poof! In a burst of special effects, you’re confronted by a doppleganger you!

    “Hi,” other!you says, “I’m you from the future.” Future!you knows enough about you that you’re convinced it is indeed you, and does something that makes it probably s/he is really from the future (predicts a couple events).

    “Wow,” you say, “my mind has been blown.”

    Actually, I’m more likely to say “fuck you Derren Brown, I’m not playing”.

  • Jack O’Connor

    Religious beliefs are just probability estimates, right? Like even the most diehard atheist is really just someone with a very low (but nonzero) opinion of the lieklihood that G-d exists. So first of all, meeting anyone from the future would decrease my certainty in everything I currently consider likely, just on principal. It might even shake my faith in / grasp of the excluded middle, in which case I might believe all propositions less than I did before!

    If future!me then tells me that he believes in X, then obviously my estimate of X will increase. It can’t increase all the way to future!my estimate, because we don’t have he same information, and there’s always a chance that future!I’m on future!drugs or something.

    I think this is more problematic if we insist on our beliefs being 0% or 100% assertions, but that seems…unrealistic?

    • keddaw

      “…atheist is really just someone with a very low (but nonzero) opinion of the lieklihood that a G-d exists…”

      A G-d. A. Stop giving such privilege to the Abrahimic deity.

      Tell me which one and I’ll give you an actual number. For example, the common Christian God is an obvious zero since it is a logical impossibility due to internal contradictions.

      • Ah. Read up on some Chesterton — a man who Terry Brooks and Neil Gaiman call a “man who knew what was going on” — and then get back to us. Take careful note of the relation, and distinction, between paradox and contradiction.

        • keddaw

          From the little Chesterton I have read I am not terribly interested in reading much more, I was not impressed.

          I shall try to look out some related writing and see what I can glean from it.

          What he can say about the good old fashioned problem of evil, the concept of hell (infinite punishment for a finite crime), the possibility that a benevolent God could justify the existence of hell, the ‘morality’ of the Old Testament and much of the New, the problem of vicarious redemption, and so on, I have no idea.

          Incidentally, trying to explain away nonsensical concepts as a paradox doth not a great thinker make. A great thinker might throw away such concepts and see what was left (like the Jefferson Bible perhaps).

  • deiseach

    I’d want to know the reasons future!me converted; I wouldn’t just go “Oh, so you’re an Acolyte Third-Rank of the Ascended Order of Scientific Magi from Cygnus Alpha? Cool!”

    I think we could agree on our basics, unless future!me did some airy dismissive handwaving along the lines of “Of course, there is no such thing as objective reality and once you accept we’re all just electrons floating around inside the Cygnus Alphans’ super-duper computer…” or the same.

    If future!me said she no longer believed in any kind of religion, I could understand that, and would want to know what had triggered this reaction above anything present!me already knew.

    And of course, if future!me had a really, really convincing reason – I might indeed become an Acolyte Third-Class of the Ascended Order of Scientific Magi from Cygnus Alpha.

  • Strange question. The truth. I would wonder if the whole think was real. Was this Satan? Was I losing my mind? It would depend on what the faith was. Islam? Hinduism? I would do some research.

    Some cult? An ultra-traditionalist schism? I would try and broaden my reading. I think there is a certain mindset that converts to those. I almost think of it as a mental disorder rather than a mindset. I would try and prevent myself from getting that disorder.

    Atheism? Secularism? That would be the hardest. It would be like being told future-me cheated on my wife and abandoned my kids. How would you process that?

    • Joe

      I think I would react the same as you. I would ask future me to let me hear his confession. Their would probably be some sin I had developed an attachment to that would cloud my judgement. I would also ask if my wife had died or if some other trauma had occurred that might cause me to give in to despair or become angry with God.

    • g

      You know, ceasing to believe that God is real doesn’t necessarily involve any kind of moral depravity. It’s not all that much like cheating on your wife and abandoning your kids.

      Continuing to believe roughly what you now believe about God and ceasing to worship him would be more like that. The (ir)religious equivalent of abandoning your wife and kids would be deciding that for some reason they *really aren’t* your wife and kids after all. Except that the evidence most people with wives and kids have for the reality of their wives and kids is (I think most theists and atheists alike would agree) less open to doubt than the evidence most theists have for the reality of their gods, so to stop believing in your wife and kids you’d need something really truly extraordinary — serious mental illness would probably be the most likely thing — and it’s not so clear that that applies to changing your mind about God.

  • After my recovery, I’d assume that any society advanced enough to shoot a projection back through time is advanced enough to fake a projection back through time.

    As for the actual question of, “Do I trust myself?” the answer would be no, at least not for now. I do not think so highly of myself that I will take my word over the word of a better authority I’ve hitherto found far more trustworthy. It may be grounds for approaching first principles again, but not more than that until I discern what diagnosis I can.

  • While not as drastic as a religious conversion, I did have a pretty drastic difference in “beliefs” between, say, the 25 year old me and the 15 year old me.

    When I was 15 I was into gangsta rap and absolutely deplored heavy metal. I thought that only white kids in the suburbs (I grew up in Harlem) listened to that and played electric guitar. Not only that, but I thought that dancing was something that I would never be able to do because I was too awkward. And forget partner dancing.

    25 year old me did a complete 180 to the previous paragraph. He(?) listens to heavy metal, plays electric guitar, and is learning how to swing dance, and hardly ever listens to rap.

    I don’t think, right now, as being closer to the 35 year old me, that I could go back in time and convince the 15 year old me to like Metallica, attempt to get him to play guitar or think he can blues dance (the 15 year old me most certainly didn’t like blues music, since that’s what grandma listens to!). The surrounding environment of the 15 year old me contributed to those beliefs, and the surrounding environment of the 25 year old me contributed to being open to exploring more possibilities.

    And if I don’t think I could convince the 15 year old me of those things without taking him out of his environment, then I wouldn’t expect some future me to be successful either, without similarly taking me out of my current environment and putting me in the environment that led to future-me’s conversion. But once that happens, I’m no longer “me”; I’m not some mind separate from my body, a mind that stays immutable but only my body changes. I am my body, and my body is intimitely connected with my surrounding environment. By extension, if my environment changes, then I also have to change a bit as well. If I’m put into the same environment that led to future-me’s conversion, then I’m no longer me. I’m future-me, which sort of defeats the thought experiment’s purpose.

  • Ted Seeber

    I would decline the discussion on the assumption that my level of evidence can’t get any more broad (and is, in fact, the reason I’m still Catholic to begin with).

    But then again, I went from being a Peter-Paul-and-Mary liberal folk music Catholic to being an evil bigoted prejudicial Catholic overnight on March 2, 2002 when Multnomah County passed the gay marriage law. (I was then, and still do, support separation of civil unions and sacramental marriage, with the state issuing the first and the church issuing the second, with overlapping but separate reasons for doing so- and the state should be UTTERLY non-discriminatory on that; just as the Church’s discrimination on the topic makes equal sense).

  • R.C.

    A lot of responses here seem to suggest that the person being addressed is an atheist who became religious. I guess that’s because the first few folk commenting happened to be atheists. But the scenario is very non-specific, isn’t it?

    What’s interesting about the answer is that IF your epistemology is sound, then what this scenario tells us about epistemology ought to work roughly the same for…

    The Catholic who became Atheist,
    The Atheist who became Orthodox Jew,
    The Orthodox Jew who became an Evangelical Protestant,
    The Evangelical Protestant who became Bahai,
    The Bahai who became Buddhist,
    the Buddhist who became Catholic,

    …and all other combinations of N and not-N, where both N and not-N are worldviews combining opinions (and the practices/pedagogy relevant to those opinions) on epistemology, cosmology, metaphysics, ethics, anthropology, and advice about how to best cope with the problems of wrongdoing, suffering, and death.

    The epistemological threshold needs to make sense under all such circumstances.

    I grant, of course, that in theory, moving from Orthodox Judaism to Messianic Judaism would require a lot less in the sense that only the messiah-hood of Yeshua would need to be established. But in practice I think that when one’s original religious (or irreligious) default “anchor point” has been thoroughly unmoored, one won’t jump to the next-nearest thing and feel just as settled as one did prior to the unmooring! One will begin to question the entire shebang. (As for whether one thoroughly questions the entire shebang…well, that’s a matter of personal courage and intellectual self-discipline.)

  • If future me offers no actual evidence, I don’t see how he could convert me. And the very fact that he is even trying to convert me would make me suspicious, since he already knows with absolute certainty that I’m going to convert in the future. Why worry about it under those circumstances. The most likely explanation is that I will at some future time be abducted and brainwashed by religious fanatics, and that future me is unconsciously attempting to warn me so that I can avoid it. He’s lying to himself because some part of him recognizes what has been done to him and wants to fix it, but the larger part needs an excuse for his actions.

    In fact, the only version of this scenario that makes any sense to me at all is one in which future you is either deceiving you or engaging in self-deception. From any other perspective, his actions make no sense – By coming back and talking to me, he is either going to achieve the same result he already has every reason to expect without intervention, or he will change the future and prevent my conversion. Since taking action to produce no change in outcome is not in my nature, the only sensible interpretation of my actions is that I’m attempting to prevent my conversion.