These things, then, which have now been explained, being sufficiently understood, we will proceed to say a little on the subject of assent and approbation, which the Greeks call συγκατάθεσις. Not that the subject itself is not an extensive one, but because the foundations have been already laid a little while ago. For when we were explaining what power there was in the senses, this point was at the same time established, that many things were comprehended and perceived by the senses, which is a thing which cannot take place without assent. Secondly, as this is the principal difference between an inanimate and an animated being, that the inanimate being does nothing, but the animated one does something (for it is impossible even to imagine what kind of animal that can be which does nothing)—either sense must be taken from it, or else assent (which is wholly in our own power) must be given. But mind is in some degree denied to those beings whom they will not allow either to feel or to assent. For as it is inevitable that one scale of a balance [pg 041] must be depressed when a weight is put in it, so the mind, too, must yield to what is evident; for just as it is impossible for any animal to forbear discerning what is manifestly suited to its nature (the Greeks call that οἰκεῖον), so it is equally impossible for it to withhold its assent to a manifest fact which is brought under its notice.
Although, if those principles which we have been maintaining are true, there is no advantage whatever in discussing assent. For he who perceives anything, assents immediately. But these inferences also follow,—that memory can have no existence without assent, no more can notions of things or arts. And what is most important of all is, that, although some things may be in our power, yet they will not be in the power of that man who assents to nothing. Where, then, is virtue, if nothing depends on ourselves? But it is above all things absurd that vices should be in the power of the agents, and that no one should do wrong except by deliberate consent to do so, and yet that this should not be the case with virtue; all the consistency and firmness of which depends on the things to which it has assented, and which it has approved. And altogether it is necessary that something should be perceived before we act, and before we assent to what is perceived; wherefore, he who denies the existence of perception or assent, puts an end to all action in life.
XIII. Now let us examine the arguments which are commonly advanced by this school in opposition to these principles. But, first of all, you have it in your power to become acquainted with what I may call the foundations of their system. They then, first of all, compound a sort of art of those things which we call perceptions, and define their power and kinds; and at the same time they explain what the character of that thing which can be perceived and comprehended is, in the very same words as the Stoics. In the next place, they explain those two principles, which contain, as it were, the whole of this question; and which appear in such a manner that even others may appear in the same, nor is there any difference between them, so that it is impossible that some of them should be perceived, and that others should not be perceived; but that it makes no difference, not only if they are in every part of the same character, but even if they cannot be distinguished.
And when these principles are laid down, then these men comprehend the whole cause in the conclusion of one argument. But this conclusion, thus compounded, runs in this way: “Of the things which are seen, some are true and some are false; and what is false cannot be perceived, but that which appears to be true is all of such a character that a thing of the same sort may seem to be also false. And as to those things which are perceived being of such a sort that there is no difference between them, it cannot possibly happen that some of them can be perceived, and that others cannot; there is, then, nothing seen which can really be perceived.”
But of the axioms which they assume, in order to draw the conclusions which they desire, they think that two ought to be granted to them; for no one objects to them. They are these: “That those perceptions which are false, cannot really be perceived;” and the second is—“Of those perceptions between which there is no difference, it is impossible that some should be of such a character that they can be perceived, and others of such a character that they cannot.”
But their other propositions they defend by numerous and varied arguments, and they likewise are two in number. One is—“Of those things which appear, some are true and others false;” the other is—“Every perception which originates in the truth, is of such a character as it might be of, though originating in what is false.” And these two propositions they do not pass by, but they expand in such a manner as to show no slight degree of care and diligence. For they divide them into parts, and those also large parts; first of all into the senses, then into those things which are derived from the senses, and from universal custom, the authority of which they wish to invalidate. Then they come to the point of laying it down that nothing can be perceived even by reason and conjecture. And these universal propositions they cut up into more minute parts. For as in our yesterday's discussion you saw that they acted with respect to the senses, so do they also act with respect to everything else. And in each separate thing which they divide into the most minute parts, they wish to make out that all these true perceptions have often false ones added to them, which are in no respect different from the true ones; and that, as they are of such a character, nothing can be comprehended.
XIV. Now all this subtlety I consider indeed thoroughly worthy of philosophy, but still wholly unconnected with the case which they advocate who argue thus. For definitions, and divisions, and a discourse which employs these ornaments, and also similarities and dissimilarities, and the subtle and fine-drawn distinctions between them, belong to men who are confident that those arguments which they are upholding are true, and firm, and certain; and not to men who assert loudly that those things are no more true than false. For what would they do if, after they had defined anything, some one were to ask them whether that definition could be transferred to something else? If they said it could, then what reason could they give why it should be a true definition? If they said no,—then it must be confessed, since that definition of what is true cannot be transferred to what is false, that that which is explained by that definition can be perceived; which is the last thing they mean.
The same thing may be said on every article of the division. For if they say that they see clearly the things about which they are arguing, and they cannot be hindered by any similarity of appearance, then they will confess that they are able to comprehend those things. But if they affirm that true perceptions cannot be distinguished from false ones, how can they go any further? For the same objections will be made to them which have been made already; for an argument cannot be concluded, unless the premises which are taken to deduce the conclusion from are so established that nothing of the same kind can be false.
Therefore, if reason, relying on things comprehended and perceived, and advancing in reliance on them, establishes the point that nothing can be comprehended, what can be found which can be more inconsistent with itself? And as the very nature of an accurate discourse professes that it will develop something which is not apparent, and that, in order the more easily to succeed in its object, it will employ the senses and those things which are evident, what sort of discourse is that which is uttered by those men who insist upon it that everything has not so much an existence as a mere appearance?
But they are convicted most of all when they assume, as consistent with each other, these two propositions which are [pg 044] so utterly incompatible: first of all,—That there are some false perceptions;—and in asserting this they declare also that there are some which are true: and secondly, they add at the same time,—That there is no difference between true perceptions and false ones. But you assumed the first proposition as if there were some difference; and so the latter proposition is inconsistent with the former, and the former with the latter.