See how Apollo, fair-hair'd God,
Draws in and bends his golden bow;
While on the left fair Dian waves her torch.
How could he have believed these things any more if they had really existed than he did when they only seemed to exist? For it is clear that at the moment his heart was not distrusting his eyes. But all these instances are cited in order to prove that than which nothing can be more certain, namely, that between true and false perceptions there is no difference at all, as far as the assent of the mind is concerned. But you prove nothing when you merely refute those false perceptions of men who are mad or dreaming, by their own recollection. For the question is not what sort of recollection those people usually have who have awakened, or those who have recovered from madness, but what sort of perception madmen or dreamers had at the moment when they were under the influence of their madness or their dream. However, we will say no more about the senses.
What is there that can be perceived by reason? You say that Dialectics have been discovered, and that that science is, as it were, an arbiter and judge of what is true and false. Of what true and false?—and of true and false on what subject? Will a dialectician be able to judge, in geometry, what is true and false, or in literature, or in music? He knows nothing about those things. In philosophy, then? What is it to him how large the sun is? or what means has he which may enable him to judge what the chief good is? What then will he judge of? Of what combination or disjunction of ideas is accurate,—of what is an ambiguous expression,—of what follows from each fact, or what is inconsistent with it? If the science of dialectics judges of these things, or things like [pg 066] them, it is judging of itself. But it professed more. For to judge of these matters is not sufficient for the resolving of the other numerous and important questions which arise in philosophy. But, since you place so much importance in that art, I would have you to consider whether it was not invented for the express purpose of being used against you. For, at its first opening, it gives an ingenious account of the elements of speaking, and of the manner in which one may come to an understanding of ambiguous expressions, and of the principles of reasoning: then, after a few more things, it comes to the sorites, a very slippery and hazardous topic, and a class of argument which you yourself pronounced to be a vicious one.
XXIX. What then, you will say; are we to be blamed for that viciousness? The nature of things has not given us any knowledge of ends, so as to enable us, in any subject whatever, to say how far we can go. Nor is this the case only in respect of the heap of wheat, from which the name is derived, but in no matter whatever where the argument is conducted by minute questions: for instance, if the question be whether a man is rich or poor, illustrious or obscure,—whether things be many or few, great or small, long or short, broad or narrow,—we have no certain answer to give, how much must be added or taken away to make the thing in question either one or the other.
But the sorites is a vicious sort of argument:—crush it, then, if you can, to prevent its being troublesome; for it will be so, if you do not guard against it. We have guarded against it, says he. For Chrysippus's plan is, when he is interrogated step by step (by way of giving an instance), whether there are three, or few, or many, to rest a little before he comes to the “many;” that is to say, to use their own language, ἡσυχάζειν. Rest and welcome, says Carneades; you may even snore, for all I care. But what good does he do? For one follows who will waken you from sleep, and question you in the same manner:—Take the number, after the mention of which you were silent, and if to that number I add one, will there be many? You will again go on, as long as you think fit. Why need I say more? for you admit this, that you cannot in your answers fix the last number which can be classed as “few,” nor the first, which amounts to [pg 067] “many.” And this kind of uncertainty extends so widely, that I do not see any bounds to its progress.
Nothing hurts me, says he; for I, like a skilful driver, will rein in my horses before I come to the end, and all the more if the ground which the horses are approaching is precipitous. And thus, too, says he, I will check myself, and not reply any more to one who addresses me with captious questions. If you have a clear answer to make, and refuse to make it, you are giving yourself airs; if you have not, even you yourself do not perceive it. If you stop, because the question is obscure, I admit that it is so; but you say that you do not proceed as far as what is obscure. You stop, then, where the case is still clear. If then all you do is to hold your tongue, you gain nothing by that. For what does it matter to the man who wishes to catch you, whether he entangles you owing to your silence or to your talking? Suppose, for instance, you were to say, without hesitation, that up to the number nine, is “few,” but were to pause at the tenth; then you would be refusing your assent to what is certain and evident, and yet you will not allow me to do the same with respect to subjects which are obscure.
That art, therefore, does not help you against the sorites; inasmuch as it does not teach a man, who is using either the increasing or diminishing scale, what is the first point, or the last. May I not say that that same art, like Penelope undoing her web, at last undoes all the arguments which have gone before? Is that your fault, or ours? In truth, it is the foundation of dialectics, that whatever is enunciated (and that is what they call ἀξίωμα, which answers to our word effatum,) is either true or false. What, then, is the case? Are these true or false? If you say that you are speaking falsely, and that that is true, you are speaking falsely and telling the truth at the same time. This, forsooth, you say is inexplicable; and that is more odious than our language, when we call things uncomprehended, and not perceived.
XXX. However, I will pass over all this. I ask, if those things cannot be explained, and if no means of judging of them is discovered, so that you can answer whether they are true or false, then what has become of that definition,—“That a proposition (effatum) is something which is either true or false?” After the facts are assumed I will add, that of them [pg 068] some are to be adopted, others impeached, because they are contrary to the first. What then do you think of this conclusion,—“If you say that the sun shines, and if you speak truth, therefore the sun does shine?” At all events you approve of the kind of argument, and you say that the conclusion has been most correctly inferred. Therefore, in teaching, you deliver that as the first mood in which to draw conclusions. Either, therefore, you will approve of every other conclusion in the same mood, or that art of yours is good for nothing. Consider, then, whether you are inclined to approve of this conclusion;—“If you say that you are a liar, and speak the truth, then you are a liar. But you do say that you are a liar, and you do speak the truth, therefore you are a liar.” How can you avoid approving of this conclusion, when you approved of the previous one of the same kind?