XXIX. In all causes, then, there are three degrees, of which one at least is to be taken for the purposes of defence, if you are limited to one. For you must either take your stand in denying that the act imputed to you has been done at all, or in denying that that which you admit to have been done has the effect which, and is of the character which, the adversary asserts. Or if there can be no doubt as to the action, or the proper name of the action, then you must deny that what you are accused of is such as he states it to be; and you must urge in your defence that what you have done must be admitted to be right. Accordingly, the first objection,—the first point of conflict with the adversary, as I may call it, depends on a kind of conjecture; the second, on a kind of definition, or description, or notion of the word; but the third plea is to be maintained by a discussion on equity, and truth, and right, and on the becomingness to man of a disposition inclined to pardon. And since he who defends ought not always to resist the accuser by some objection, or denial, or definition, or opposite principles of equity, but should also at times advance general principles on which he founds his defence, the first kind of objection has in it the principle of asserting the charge to be unjust, an absolute denial of the fact; the second urges that the definition given by the adversary does not apply to the action in question the third consists in the advocate defending the action as having been rightly done, without raising any dispute as to the name of it.
In the next place, the accuser must oppose to every argument that, which if it were not in the accusation, would prevent, there being any cause at all. Therefore, those arguments which are brought forward in that way, are said to be the foundations of causes, although those which are brought forward in opposition to the plan of the defence, are no more so in reality than the principles of the defence themselves; but for the sake of distinction, we call that a reason which is urged by the party on his trial in the way of demurrer for the sake of repelling an accusation; and unless he had such a refuge he would have nothing to allege by way of defence: but the foundation of his defence is that which is alleged by way of undermining the arguments of the adversary, without which the accusation can have no ground to stand upon.