Five Thousand B.C. and Other Philosophical Fantasies

by Raymond Smullyan

  EPISTEMOLOGIST: Now I don’t understand you. Do you accept this Eastern idea or don’t you?

  ANDRICUS: I told you before, yes and no, by which I mean that in a way I do and in a way I don’t. Obviously, the kind of identity the epistemologist used is the Leibnizian notion, which is the notion used by most modern logicians. According to this notion, two things are identical if everything that is true of one of them is also true of the other. In this sense of identity, of course my neighbor is not identical with myself, for the very reason mentioned by the epistemologist.

  EPISTEMOLOGIST: Of course I was using the notion of identity in the standard sense. What other sense is there? Any false statement can be made true if one simply changes the meaning of all

  —or even some—of the words involved. Perhaps you mean by identical just what most of us mean by different. In that nonstandard sense of the word identical I will grant you that my neighbor is identical with myself, which now simply means that my neighbor is different from myself.

  ANDRICUS: Please now, you hardly think that I am so simpleminded as not to be aware of this completely trivial way of making any statement true. Do you honestly believe that when I affirm the statement, “My neighbor is identical with myself,” that by identical I mean different?

  EPISTEMOLOGIST: No, of course I don’t believe you are doing anything quite that preposterous! But what are you doing? Since you admit that you are not using the notion of identity in the standard sense, you must be using it in some other sense So instead of tampering with language, why don’t you instead use the standard word, or group of words, to describe the notion you have in mind?

  ANDRICUS: I assure you that I am not being perverse or trying to be mysterious. The honest fact is that I don’t know of any other word to convey my meaning.

  EPISTEMOLOGIST: And I can assure you that I am not trying to be skeptical for the sake of being skeptical, nor am I trying to be un-understanding. I genuinely believe it possible that you are trying to explicate an extremely important notion, but so far I cannot understand it. Is there nothing you can say to make the task any easier for us?

  ANDRICUS: There may be something, though I don’t know how much it will help. In the first place, though I admitted that my use of the notion of identity is not the Leibnizian notion that logicians use, it does not quite follow that my use is nonstandard; I very much doubt that the Leibnizian notion is the only standard one.

  EPISTEMOLOGIST: What other standard notion is there?

  ANDRICUS: There is the following: Ask an average adult whether he is the same person he was when he was a child, or whether he is a different person. Some will answer, “Of course I am different; I am taller, fatter, older, wiser, and so forth.” Others will answer, “Of course I am the same person. Obviously, I have changed in the meantime, but still I am really the same person.” My point is that enough people will give the latter answer for it to qualify as standard. Now, this notion of being the same person I was when I was a child is obviously not the Leibnizian notion of identity. The adult I and the childhood I do not have all properties in common. In particular, if someone sticks a pin into my present body, the childhood I did not feel it, and if someone sticks a pin in the childhood I, the present I does not feel it. Yet there is, I think, a very real and very important sense in which the childhood I and the adult I are the same. It is this notion of identity that comes far closer to the notion of sameness inherent in the statement, “My neighbor is myself.”

  EPISTEMOLOGIST: I think I understand this other notion of identity (though there are those who would question it). But the two contexts are so very different! In the case of a child becoming an adult, there is an obvious continuity that can easily and naturally give rise to this notion. But comparing you with your neighbor, this continuity is obviously absent, hence how can this other notion of identity apply?

  ANDRICUS: Good question! I would answer it by saying that although this other notion of identity would naturally occur to one as a result of continuous transformation, it does not therefore follow that the notion is applicable only in this situation; it may also apply to myself and my neighbor.

  FIRST PHILOSOPHER: I think that using pure reason we cannot make much more headway with this problem. At this point, I am afraid that I must ask you an irritatingly practical question. What evidence do you have that your neighbor is yourself?

  ANDRICUS: None whatsoever!

  FIRST PHILOSOPHER: Then why in heaven’s name do you believe it?

  ANDRICUS: Why? I don’t believe I know why. It just seems right to me.

  FIRST PHILOSOPHER: And from the fact that it seems right to you, you have the audacity to conclude that it is right?

  ANDRICUS: Of course not! Of course I know that because something seems right to me it does not follow that it is true. You act as if I started from the premise, “I believe it,” and drew as a conclusion, “It is true.” But I have done nothing of the sort. The statement, “I believe it,” is neither a premise nor a conclusion; it is simply a fact, since I do believe it—at least I do much of the time.

  FIRST PHILOSOPHER: You mean to say that you believe it some of the time, and some of the time you don’t?

  ANDRICUS: I’m afraid so!

  FIRST PHILOSOPHER: What do you believe at this very moment; do you believe it or not?

  ANDRICUS: I’m afraid that at this very moment I feel so silly and on the defensive that I really cannot say whether I believe it now or not.

  FIRST PHILOSOPHER: I find it rather ironical that all of us here have been wasting our precious time in what we honestly thought was a genuine objective philosophical discussion, and then it turns out that all you have been saying has led up to a mere personal idea, and moreover, one that by your own admission you do not even consistently maintain.

  ANDRICUS: In all fairness to myself, I must correct you. I told you at the very beginning of the conversation that I made no claim whatsoever; I am merely trying to understand the Eastern mystic viewpoint.

  SECOND PHILOSOPHER (to First Philosopher): I’m afraid Andricus is right about that, and I must say your attitude can hardly be described as sympathetic. But I can also understand your disappointment in expecting a purely objective analysis of the question.

  FIRST PHILOSOPHER: Well, I’m sorry if I was overly abrupt, yet I cannot but feel that you, Andricus, instead of consulting us philosophers about this problem should have consulted a psychologist or psychiatrist since your problem is obviously not philosophical but purely psychological.

  SECOND PHILOSOPHER: I perfectly agree that the problem is psychological rather than philosophical. Fortunately, I have had some psychiatric training, so I think I can be of some help here.

  Look, Andricus, you obviously have some enormously strong motivation for wanting to understand and even believe the statement, “Thy neighbor is thyself.” You have gone to fantastic lengths in first discussing its ethical ramifications and then bringing in all these weird science fiction fantasies to, as you say, suggest its meaning. Then you admit having no evidence for its truth and not even a clear knowledge of what it means to be true, and you admit that whatever understanding you sometimes have of it is elusive and inconstant. Despite all these difficulties—which you yourself evidently realize—you nevertheless cling to the idea as you would to something very precious. So I must ask you to ask yourself very honestly, What is your real motive for embracing this principle?

  ANDRICUS: Without having to be as introspective as you suggest, I can certainly think of a very good motive, but I would call this motive philosophical rather than psychological. SECOND PHILOSOPHER: What motive is that?

  ANDRICUS: I was just about to tell you. The statement, “My neighbor is myself,” seems to me the only alternative to—of all things—solipsism !

  FIRST PHILOSOPHER: Good God, you can’t be serious!

  MORALIST: Now really, you are going a bit too far!

  EPISTEMOLOGIST: How can this statement possibly relate to solipsism ?

/>   ANDRICUS: I was just about to tell you. All my life I have never been able to understand how any mind could possibly conceive of anything outside its own experience. How can one mind even think of another; what sort of image of it could it possibly have? How could I in all honesty believe in the existence of other minds when I cannot even conceive of them?

  EPISTEMOLOGIST: What’s wrong with the standard argument by analogy? You see other bodies acting sufficiently like your own for you to make a probabilist inference that they have other minds, too.

  ANDRICUS: Please, you don’t understand! No probabilist argument could help me in the least! In the first place, probabilist arguments have never carried with me the slightest conviction when applied to conclusions that themselves are not empirical.

  EPISTEMOLOGIST: I am not sure I understand you.

  ANDRICUS: I mean to say that when it comes to predicting directly observable events like the cast of a die, the outcome of spinning a roulette wheel, or the rising of the sun tomorrow, probabilist arguments really carry with me intuitive conviction; they really are causative factors in producing within me psychological expectation. But when applied to conclusions that might be called metaphysical in nature, as for example, whether external objects really exist, whether minds really exist, whether minds or souls survive bodily death, or whether other minds exist, probabilist arguments just don’t carry with me the same type of intuitive conviction. I understand perfectly what is meant by saying that if I throw a die, the probability is I in 6 that the number 5 will come up, or that the probability of 17 coming up on a roulette wheel is 1 in 37. But what on earth does it mean to say that the probability that external objects exist is such and such, or that the probability is so and so that other minds exist?

  FIRST PHILOSOPHER: But how could we know such things except on a probabilist basis? Everyone who has seriously thought about the matter knows, for example, that solipsism is not logically refutable. From the statement, “My mind is the only one in existence,” one certainly cannot derive a logical contradiction. Therefore, I cannot know with logical certainty but only with very high probability that other minds exist. This probability is high enough for my comfort.

  ANDRICUS: The probability that other minds exist is high enough for you? Just how high is it, anyhow? Would you care to give a numerical estimate of it? Of course not! I still say that probability, as well as logic, is utterly irrelevant to the problem. Most people believe as a matter of course that other minds exist; it would not even occur to them to doubt it, nor to consider, of all things, its probability. Indeed, if an average person should be asked by a philosopher, “How do you know that others minds exist?” he will usually look at the philosopher as if he is crazy (and, in a way, he may be right). It is only when one feels the need to justify one’s metaphysical beliefs—say, the belief in other minds—that one brings in logic and probability, but these are only afterthoughts or rationalizations and, I maintain, very bad ones at that. The fact is that such beliefs almost always occur prior to the arguments found for their justification.

  MORALIST: I also believe that the probabilist arguments used to justify the existence of other minds are very poor—indeed, downright immoral. It is simply not very nice to doubt the existence of other minds!

  FIRST PHILOSOPHER (to Moralist): I’m sorry that I cannot go along with this. Whether other minds exist or not is a fact, and I cannot use a moral argument to establish a question of fact. Besides, to say that it is not nice or that it is immoral to doubt the existence of other minds makes sense only if other minds do in fact exist. If there really were no other minds, why would it be morally wrong to know or to believe this fact? It seems to me that you are putting the cart before the horse. To know whether it is morally right to believe in other minds, it must be first settled whether there are other minds, and this, I maintain, can be settled only on the basis of high probability.

  ANDRICUS: And I maintain that it cannot. But it is silly for us to argue this point now. If you find a probabilist argument necessary for maintaining your belief in other minds, it should hardly be my function to try to deprive you of it. But as I have said before, such an argument carries absolutely no conviction with me.

  FIRST PHILOSOPHER: In that case, what reasons do you have to justify your belief in other minds? Or are you still a solipsist?

  ANDRICUS: I still have not made my situation clear to you. I don’t require any reasons or justification whatever for the belief in other minds!

  FIRST PHILOSOPHER: Then you are not being rational!

  ANDRICUS: Call it what you like; we can argue about this another time, since the question of my rationality is so irrelevant to what I am trying to say. As a child, I never had the slightest doubt about the existence of other minds; I took it completely as a matter of course, as most people do. Would you call them irrational for having this belief just because they have never figured out reasons to justify it?

  FIRST PHILOSOPHER: Then I am more puzzled than ever. If, as you say, you don’t need rational arguments to justify this belief, then what on earth stops you from having it? Why do you have a problem with solipsism at all? Since you don’t need any probabilist argument, what stops you from simply accepting the existence of other minds without any inductive evidence?

  ANDRICUS: Because of what I told you before. To me, the problem never was, “Are there other minds?” but “Could there be other minds?” Once I believe that other minds could exist, then I would not have the slightest doubt that other minds do exist.

  FIRST PHILOSOPHER: This is the weirdest argument I have ever heard! You mean to say that you believe that everything that is possible is actual, that everything that could exist does exist?

  ANDRICUS: Of course not! Why do you jump to such a silly generality? I am not saying that everything that can exist does exist. I am just saying that other minds happen to be one of those things whose possible existence would to me be enough to ensure their actual existence. In other words, my mind happens to be so constituted, whether rightly or wrongly, rationally or irrationally, that if I can accept the possibility of other minds, then I automatically accept their actuality. I am not here drawing any inference or proposing any argument; I am just telling you how I do as a matter of fact think. Normally, I don’t do this, but you must recall that I was asked the psychological question of what are my motivations for my interest in the statement, “Thy neighbor is thyself.”

  SECOND PHILOSOPHER: So far, so good. I personally could not make the step from the possibility of other minds to their actual existence, but if you say that you can, who can quarrel with the fact that you do? But I still cannot understand your difficulties in the first place in believing that other minds are even possible. Why should they be impossible?

  ANDRICUS: Because, as I told you before, how can I even conceive anything outside of my own experience; hence how can I possibly believe it?

  MORALIST: Isn’t your attitude just a bit on the egocentric side?

  ANDRICUS: Of course it is, and of course I know it! But do you think that knowing it makes matters any easier or less painful? As was said before, how can any moral argument clear up an epistemological difficulty? A moral argument might indeed succeed in making one feel guilty for holding certain views, but it cannot possibly succeed in locating the actual source of one’s error. Also—since morality has again come up—I think that as an ex-solipsist I should tell you that there is much moral and psychological misunderstanding of the actual state of mind of the solipsist. You act as if the solipsist is an aggressive individual who is trying to aggrandize himself by rejecting others. Has it never occurred to you that a solipsist may be an extremely lonely creature who is desperately trying but does not know how to succeed in accepting others?

  MORALIST: Oh come on now with your sentimental hogwash! The typical solipsist goes swaggering around with a superior smile saying, “I alone exist, you do not!” Can you seriously expect me to believe that he is anything like the psychological type you descri
be?

  ANDRICUS: The typical solipsist? How do you know what the typical solipsist is? I doubt very much whether the type you describe is the typical solipsist. I’m afraid that the typical solipsist does not go around publicly announcing his solipsism but bears it shamefully in silence. I wonder whether even the type you do mention is really so vain and proud, underneath it all, or whether he is not covering up a desperate fear and insecurity?

  MORALIST: It seems these days that one can excuse any vanity by simply saying that it is only a cover-up for an underlying humility.

  SECOND PHILOSOPHER: Leaving aside these moral questions, I would like to return to the basic matter. How does the statement, “Thy neighbor is thyself,” help you to believe that the existence of other minds is possible?

  ANDRICUS: Because if this statement is true, it means that other minds do exist! There can be millions, trillions of them, only they are all identical with my own!

  FIRST PHILOSOPHER: Good grief! This is the most utterly insane solution of the solipsism problem that I ever have heard!

  MORALIST (gleefully): The man’s egotism knows no bounds! Now he is saying that his mind is the only one in existence, and no other minds exist in the universe; if they do, the only way that they can exist is if they are identical with his! So his mind is still the only mind in the universe! If this is not egotism pushed to its utter and fantastic logical extreme, I don’t know what is! Perhaps it should no longer be called egotism but superegotism! I have never before in my entire life heard such a self-aggrandizing doctrine! Furthermore, his brand of solipsism (and after all, it is a brand of solipsism) should perhaps be called supersolipsism. Compared with standard solipsism, I would say that it is even worse and more vicious!

  ANDRICUS (to Moralist): Strange as it may seem, I tend to agree with everything you have just said except for your final remark. My viewpoint might indeed be described as pushing egotism to its extreme logical limit. But what is necessarily so bad about that? I have long suspected—as have many others—that altruism is, in the last analysis, nothing more nor less than egotism expanded to its ultimate limit. I also like the terms that you have just coined: superegotism and supersolipsism. But when you compare supersolipsism with what you call standard solipsism and declare it to be even more vicious, I believe you overlook an important point. When two standard solipsists get together in an argument, each claims the other to be wrong. But I as a supersolipsist can attend a congress of a thousand solipsists, each one shouting, “I am the only mind in existence,” and I can happily agree with all of them! Each may think that all the rest of them are wrong, but I can know that all of them are right since they don’t actually contradict each other but only think that they do. Each one thinks that he is using the word I in a different sense, but in reality they are all using it in the same sense; they mean the same thing by it but don’t know it. If I should have the really good fortune of attending a congress of a thousand supersolipsists, it would be even better. Now, when each one said, “I am the only mind in existence,” each one would not only be right but would know that all the others were also right! I think that rather than call them supersolipsists, I would prefer to call them enlightened solipsists. Yes, from now on I shall refer to such people as enlightened solipsists. Just think of it! A whole world—a whole universe—peopled with enlightened solipsists! What could be more beautiful!