XLIII. What is assumed as something credible is invalidated, if it is either manifestly false, in this way:—"There is the one who would not prefer riches to wisdom." Or on the opposite side something credible may be brought against it, in this manner—"Who is there who is not more desirous of doing his duty than of acquiring money?" Or it may be utterly and absolutely incredible, as if some one, who it is notorious is a miser, were to say that he had neglected the acquisition of some large sum of money for the sake of performing some inconsiderable duty. Or if that which happens in some circumstances, and to some persons, were asserted to happen habitually in all cases and to everybody, in this way.—'Those men who are poor have a greater regard for money than for duty.' 'It is very natural that a murder should have been committed in that which is a desert place.' How could a man be murdered in a much frequented place? Or if a thing which is done seldom is asserted never to be done at all, as Curius asserts in his speech in behalf of Fulvius, where he says, "No one can fall in love at a single glance, or as he is passing by."
But that which is assumed as a proof may be invalidated by a recurrence to the same topics as those by which it is sought to be established. For in a proof the first thing to be shown is that it is true, and in the next place, that it is one especially affecting the matter which is under discussion, as blood is a proof of murder in the next place, that that has been done which ought not to have been, or that has not been done which ought to have been and last of all, that the person accused was acquainted with the law and usages affecting the matter which is the subject of inquiry. For all these circumstance are matters requiring proof, and we will explain them more carefully, when we come to speak about conjectural statements separately. Therefore, each of these points in a reprehension of the statement of the adversary must be laboured, and it must be shown either that such and such a thing is no proof, or that it is an unimportant proof, or that it is favourable to oneself rather than to the adversary, or that it is altogether erroneously alleged, or that it may be diverted so as to give grounds to an entirely different suspicion.
XLIV. But when anything is alleged as a proper object of comparison, since that is a class of argument which turns principally on resemblance, in reprehending the adversity it will be advisable to deny that there is any resemblance at all to the case with which it is attempted to institute the comparison. And that may be done if it be proved to be different in genus or in nature, or in power, or in magnitude, or in time or place, or with reference to the person affected, or to the opinions generally entertained of it. And if it be shown also in what classification that which is brought forward on account of the alleged resemblance and in what place too the whole genus with reference to which it is brought forward, ought to be placed. After that it will be pointed out how the one thing differs from the other, from which we shall proceed to show that a different opinion ought to be entertained of that which is brought forward by way of comparison, and of that to which it is sought to be compared. And this sort of argument we especially require when that particular argumentation which is carried on by means of induction is to be reprehended. If any previous decision be alleged, since these are the topics by which it is principally established, the praise of those who have delivered such decision, the resemblance of the matter which is at present under discussion to that which has already been the subject of the decision referred to, that not only the decision is not found fault with because it is mentioned, but that it is approved of by every one, and by showing too, that the case which has been already decided is a more difficult and a more important one than that which is under consideration now. It will be desirable also to invalidate it by arguments drawn from the contrary topics, if either truth or probability will allow us to do so. And it will be necessary to take care and notice whether the matter which has been decided has any real connexion with that which is the present subject of discussion, and we must also take care that no case is adduced in which any error has been committed, so that it should seem that we are passing judgment on the man himself who has delivered the decision referred to.
It is desirable further to take care that they do not bring forward some solitary or unusual decision when there have been many decisions given the other way. For by such means as this the authority of the decision alleged can be best invalidated. And it is desirable that those arguments which are assumed as probable should be handled in this way.
XLV. But those which are brought forward as necessary, if they are only imitations of a necessary kind of argumentation and are not so in reality, may be reprehended in this manner. In the first place, the summing up, which ought to take away the force of the admissions you have made if it be a correct one, will never be reprehended, if it be an incorrect one it may be attacked by two methods, either by conversion or by the invalidating one portion of it. By conversion, in this way.
"For if the man be modest, why should you
Attack so good a man? And if his heart
And face be seats of shameless impudence,
Then what avails your accusation
Of one who views all fame with careless eye?"
In this case, whether you say that he is a modest man or that he is not, he thinks that the unavoidable inference is that you should not accuse him. But that may be reprehended by conversion thus—"But indeed, he ought to be accused, for if he be modest, accuse him, for he will not treat your imputations against him lightly, but if he has a shameless disposition of mind, still accuse him, for in that case he is not a respectable man."
And again, the argument may be reprehended by an invalidating of the other part of it—"But if he is a modest man, when he has been corrected by your accusation he will abandon his error." An enumeration of particulars is understood to be faulty if we either say that something has been passed over which we are willing to admit, or if some weak point has been included in it which can be contradicted, or if there is no reason why we may not honestly admit it. Something is passed over in such an enumeration as this.—"Since you have that horse, you must either have bought it, or have acquired it by inheritance, or have received it as a gift, or he must have been born on your estate, or, if none of these alternatives of the case, you must have stolen it. But you did not buy it, nor did it come to you by inheritance, nor was it foaled on your estate, nor was it given to you as a present, therefore you must certainly have stolen it."
This enumeration is fairly reprehended, if it can be alleged that the horse was taken from the enemy, as that description of booty is not sold. And if that be alleged, the enumeration is disproved, since that matter has been stated which was passed over in such enumeration.
XLVI. But it will also be reprehended in another manner, if any contradictory statement is advanced; that is to say, just by way of example, if, to continue arguing from the previous case, it can be shown that the horse did come to one by inheritance, or if it should not be discreditable to admit the last alternative, as if a person, when his adversaries said,—"You were either laying an ambush against the owner, or you were influenced by a friend, or you were carried away by covetousness," were to confess that he was complying with the entreaties of his friend.