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 he 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. 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?
EPISTEMOLOCIST: 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!
Scene 4. (Later in the day at a psychiatrist’s office.)
FRANK: Doctor, I am terribly worried about a friend of mine. He calls himself an “experimental epistemologist.”
DOCTOR: Oh, the experimental epistemologist. There is only one in the world. I know him well!
FRANK: That is a relief. But do you realize that he has constructed a mind-reading device that he now directs to his own brain, and whenever one asks him what he thinks, believes, feels, is afraid of, and so on, he has to consult the machine first before answering? Don’t you think this is pretty serious?