An Epistemological Nightmare - #3

Source: MIT
Click here to read scene 2.

By Raymond M. Smullyan, 1982

Scene 3

Frank comes back several months later to the home of the epistemologist.
Epistemologist:
    How delightful to see you! Please sit down.

Frank (seated):
    I have been thinking of our last discussion, and there is much I wish to clear up. To begin with, I discovered an inconsistency in some of the things you said.

Epistemologist:
    Delightful! I love inconsistencies. Pray tell!

Frank:
    Well, you claimed that although my belief sentences were false, I did not have any actual beliefs that are false. If you had not admitted that the book actually is red, you would have been consistent. But your very admission that the book is red, leads to an inconsistency.

Epistemologist:
    How so?

Frank:
    Look, as you correctly pointed out, in each of my belief sentences "I believe it is red," "I believe that I believe it is red," the falsity of each one other than the first saves me from an erroneous belief in the proceeding one. However, you neglected to take into consideration the first sentence itself. The falsity of the first sentence "I believe it is red," in conjunction with the fact that it is red, does imply that I do have a false belief.

Epistemologist:
    I don't see why.

Frank:
    It is obvious! Since the sentence "I believe it is red" is false, then I in fact believe it is not red, and since it really is red, then I do have a false belief. So there!

Epistemologist (disappointed):
    I am sorry, but your proof obviously fails. Of course the falsity of the fact that you believe it is red implies that you don't believe it is red. But this does not mean that you believe it is not red!

Frank:
    But obviously I know that it either is red or it isn't, so if I don't believe it is, then I must believe that it isn't.

Epistemologist:
    Not at all. I believe that either Jupiter has life or it doesn't. But I neither believe that it does, nor do I believe that it doesn't. I have no evidence one way or the other.

Frank:
    Oh well, I guess you are right. But let us come to more important matters. I honestly find it impossible that I can be in error concerning my own beliefs.

Epistemologist:
    Must we go through this again? I have already patiently explained to you that you (in the sense of your beliefs, not your statements) are not in error.

Frank:
    Oh, all right then, I simply do not believe that even the statements are in error. Yes, according to the machine they are in error, but why should I trust the machine?

Epistemologist:
    Whoever said you should trust the machine?

Frank:
    Well, should I trust the machine?

Epistemologist:
    That question involving the word "should" is out of my domain. However, if you like, I can refer you to a colleague who is an excellent moralist--he may be able to answer this for you.

Frank:
    Oh come on now, I obviously didn't mean "should" in a moralistic sense. I simply meant "Do I have any evidence that this machine is reliable?"

Epistemologist:
    Well, do you?

Frank:
    Don't ask me! What I mean is should you trust the machine?

Epistemologist:
    Should I trust it? I have no idea, and I couldn't care less what I should do.

Frank:
    Oh, your moralistic hangup again. I mean, do you have evidence that the machine is reliable?

Epistemologist:
    Well of course!

Frank:
    Then let's get down to brass tacks. What is your evidence?

Epistemologist:
    You hardly can expect that I can answer this for you in an hour, a day, or a week. If you wish to study this machine with me, we can do so, but I assure you this is a matter of several years. At the end of that time, however, you would certainly not have the slightest doubts about the reliability of the machine.

Frank:
    Well, possibly I could believe that it is reliable in the sense that its measurements are accurate, but then I would doubt that what it actually measures is very significant. It seems that all it measures is one's physiological states and activities.

Epistemologist:
    But of course, what else would you expect it to measure?

Frank:
    I doubt that it measures my psychological states, my actual beliefs.

Epistemologist:
    Are we back to that again? The machine does measure those physiological states and processes that you call psychological states, beliefs, sensations, and so forth.

Frank:
    At this point I am becoming convinced that our entire difference is purely semantical. All right, I will grant that your machine does correctly measure beliefs in your sense of the word "belief," but I don't believe that it has any possibility of measuring beliefs in my sense of the word "believe." In other words I claim that our entire deadlock is simply due to the fact that you and I mean different things by the word "belief."

Epistemologist:
    Fortunately, the correctness of your claim can be decided experimentally. It so happens that I now have two brain-reading machines in my office, so I now direct one to your brain to find out what you mean by "believe" and now I direct the other to my own brain to find out what I mean by "believe," and now I shall compare the two readings. Nope, I'm sorry, but it turns out that we mean exactly the same thing by the word "believe."

Frank:
    Oh, hang your machine! Do you believe we mean the same thing by the word "believe"?

Epistemologist:
    Do I believe it? Just a moment while I check with the machine. Yes, it turns out I do believe it.

Frank:
    My goodness, do you mean to say that you can't even tell me what you believe without consulting the machine?

Epistemologist:
    Of course not.

Frank:
    But most people when asked what they believe simply tell you. Why do you, in order to find out your beliefs, go through the fantastically roundabout process of directing a thought-reading machine to your own brain and then finding out what you believe on the basis of the machine readings?

Epistemologist:
    What other scientific, objective way is there of finding out what I believe?

Frank:
    Oh, come now, why don't you just ask yourself?

Epistemologist (sadly):
    It doesn't work. Whenever I ask myself what I believe, I never get any answer!

Frank:
    Well, why don't you just state what you believe?

Epistemologist:
    How can I state what I believe before I know what I believe?

Frank:
    Oh, to hell with your knowledge of what you believe; surely you have some idea or belief as to what you believe, don't you?

Epistemologist:
    Of course I have such a belief. But how do I find out what this belief is?

Frank:
    I am afraid we are getting into another infinite regress. Look, at this point I am honestly beginning to wonder whether you may be going crazy.

Epistemologist:
    Let me consult the machine. Yes, it turns out that I may be going crazy.

Frank:
    Good God, man, doesn't this frighten you?

Epistemologist:
    Let me check! Yes, it turns out that it does frighten me.

Frank:
    Oh please, can't you forget this damned machine and just tell me whether you are frightened or not?

Epistemologist:
    I just told you that I am. However, I only learned of this from the machine.

Frank:
    I can see that it is utterly hopeless to wean you away from the machine. Very well, then, let us play along with the machine some more. Why don't you ask the machine whether your sanity can be saved?

Epistemologist:
    Good idea! Yes, it turns out that it can be saved.

Frank:
    And how can it be saved?

Epistemologist:
    I don't know, I haven't asked the machine.

Frank:
    Well, for God's sake, ask it!

Epistemologist:
    Good idea. It turns out that...

Frank:
    It turns out what?

Epistemologist:
    It turns out that...

Frank:
    Come on now, it turns out what?

Epistemologist:
    This is the most fantastic thing I have ever come across! According to the machine the best thing I can do is to cease to trust the machine!

Frank:
    Good! What will you do about it?

Epistemologist:
    How do I know what I will do about it, I can't read the future?

Frank:
    I mean, what do you presently intend to do about it?

Epistemologist:
    Good question, let me consult the machine. According to the machine, my current intentions are in complete conflict. And I can see why! I am caught in a terrible paradox! If the machine is trustworthy, then I had better accept its suggestion to distrust it. But if I distrust it, then I also distrust its suggestion to distrust it, so I am really in a total quandary.

Frank:
    Look, I know of someone who I think might be really of help in this problem. I'll leave you for a while to consult him. Au revoir!

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