An Epistemological Nightmare - #2

Source: MIT
Click here to read scene 1.

By Raymond M. Smullyan, 1982

Scene 2

(A few weeks later.) Frank is in a laboratory in the home of an experimental epistemologist. (You will soon find out what that means!) The epistemologist holds up a book and also asks, "What color is this book?" Now, Frank has been earlier dismissed by the eye doctor as "cured." However, he is now of a very analytical and cautious temperament, and will not make any statement that can possibly be refuted. So Frank answers, "It seems red to me."

Epistemologist:
    Wrong!

Frank:
    I don't think you heard what I said. I merely said that it seems red to me.

Epistemologist:
    I heard you, and you were wrong.

Frank:
    Let me get this clear; did you mean that I was wrong that this book is red, or that I was wrong that it seems red to me?

Epistemologist:
    I obviously couldn't have meant that you were wrong in that it is red, since you did not say that it is red. All you said was that it seems red to you, and it is this statement which is wrong.

Frank:
    But you can't say that the statement "It seems red to me" is wrong.

Epistemologist:
    If I can't say it, how come I did?

Frank:
    I mean you can't mean it.

Epistemologist:
    Why not?

Frank:
    But surely I know what color the book seems to me!

Epistemologist:
    Again you are wrong.

Frank:
    But nobody knows better than I how things seem to me.

Epistemologist:
    I am sorry, but again you are wrong.

Frank:
    But who knows better than I?

Epistemologist:
    I do.

Frank:
    But how could you have access to my private mental states?

Epistemologist:
    Private mental states! Metaphysical hogwash! Look, I am a practical epistemologist. Metaphysical problems about "mind" versus "matter" arise only from epistemological confusions. Epistemology is the true foundation of philosophy. But the trouble with all past epistemologists is that they have been using wholly theoretical methods, and much of their discussion degenerates into mere word games. While other epistemologists have been solemnly arguing such questions as whether a man can be wrong when he asserts that he believes such and such, I have discovered how to settle such questions experimentally.

Frank:
    How could you possibly decide such things empirically?

Epistemologist:
    By reading a person's thoughts directly.

Frank:
    You mean you are telepathic?

Epistemologist:
    Of course not. I simply did the one obvious thing which should be done, viz. I have constructed a brain-reading machine--known technically as a cerebroscope--that is operative right now in this room and is scanning every nerve cell in your brain. I thus can read your every sensation and thought, and it is a simple objective truth that this book does not seem red to you.

Frank (thoroughly subdued):
    Goodness gracious, I really could have sworn that the book seemed red to me; it sure seems that it seems read to me!

Epistemologist:
    I'm sorry, but you are wrong again.

Frank:
    Really? It doesn't even seem that it seems red to me? It sure seems like it seems like it seems red to me!

Epistemologist:
    Wrong again! And no matter how many times you reiterate the phrase "it seems like" and follow it by "the book is red" you will be wrong.

Frank:
    This is fantastic! Suppose instead of the phrase "it seems like" I would say "I believe that." So let us start again at ground level. I retract the statement "It seems red to me" and instead I assert "I believe that this book is red." Is this statement true or false?

Epistemologist:
    Just a moment while I scan the dials of the brain-reading machine--no, the statement is false.

Frank:
    And what about "I believe that I believe that the book is red"?

Epistemologist (consulting his dials):
    Also false. And again, no matter how many times you iterate "I believe," all these belief sentences are false.

Frank:
    Well, this has been a most enlightening experience. However, you must admit that it is a little hard on me to realize that I am entertaining infinitely many erroneous beliefs!

Epistemologist:
    Why do you say that your beliefs are erroneous?

Frank:
    But you have been telling me this all the while!

Epistemologist:
    I most certainly have not!

Frank:
    Good God, I was prepared to admit all my errors, and now you tell me that my beliefs are not errors; what are you trying to do, drive me crazy?

Epistemologist:
    Hey, take it easy! Please try to recall: When did I say or imply that any of your beliefs are erroneous?

Frank:
    Just simply recall the infinite sequence of sentences: (1) I believe this book is red; (2) I believe that I believe this book is red; and so forth. You told me that every one of those statements is false.

Epistemologist:
    True.

Frank:
    Then how can you consistently maintain that my beliefs in all these false statements are not erroneous?

Epistemologist:
    Because, as I told you, you don't believe any of them.

Frank:
    I think I see, yet I am not absolutely sure.

Epistemologist:
    Look, let me put it another way. Don't you see that the very falsity of each of the statements that you assert saves you from an erroneous belief in the preceding one? The first statement is, as I told you, false. Very well! Now the second statement is simply to the effect that you believe the first statement. If the second statement were true, then you would believe the first statement, and hence your belief about the first statement would indeed be in error. But fortunately the second statement is false, hence you don't really believe the first statement, so your belief in the first statement is not in error. Thus the falsity of the second statement implies you do not have an erroneous belief about the first; the falsity of the third likewise saves you from an erroneous belief about the second, etc.

Frank:
    Now I see perfectly! So none of my beliefs were erroneous, only the statements were erroneous.

Epistemologist:
    Exactly.

Frank:
    Most remarkable! Incidentally, what color is the book really?

Epistemologist:
    It is red.

Frank:
    What!

Epistemologist:
    Exactly! Of course the book is red. What's the matter with you, don't you have eyes?

Frank:
    But didn't I in effect keep saying that the book is red all along?

Epistemologist:
    Of course not! You kept saying it seems red to you, it seems like it seems red to you, you believe it is red, you believe that you believe it is red, and so forth. Not once did you say that it is red. When I originally asked you "What color is the book?" if you had simply answered "red," this whole painful discussion would have been avoided.

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