discreditable error of all.  Conciseness in arrangement is preserved if the general classes of facts are clearly laid down, and are not entangled in a promiscuous manner with the subordinate divisions.  For a class is that which embraces many subordinate divisions as, “an animal.”  A subordinate division is that which is contained in the class as “a horse.”  But very often the same thing may be a class to one person, and a subordinate division to another.  For “man” is a subordinate division of “animal,” but a class as to “Theban,” or “Trojan.”

XXIII And I have been more careful in laying down this definition, in order that after it has been clearly comprehended with reference to the general arrangement, a conciseness as to classes or genera may be preserved throughout the arrangement.  For he who arranges his oration in this manner—­“I will prove that by means of the covetousness and audacity and avarice of our adversaries, all sorts of evils have fallen on the republic,” fails to perceive that in this arrangement of his, when he intended to mention only classes, he has joined also a mention of a subordinate division.  For covetousness is the general class under which all desires are comprehended, and beyond all question avarice is a subordinate division of that class.

We must therefore avoid, after having mentioned a universal class, then, in the same arrangement, to mention along with it any one of its subordinate divisions, as if it were something different and dissimilar.  And if there are many subordinate divisions to any particular class, after that has been simply explained in the first arrangement of the oration, it will be more easily and conveniently arranged when we come to the subsequent explanation in the general statement of the case after the division.  And this, too, concerns the subject of conciseness, that we should not undertake to prove more things than there is any occasion for, in this way—­“I will prove that the opposite party were able to do what we accuse them of, and had the inclination to do it, and did it.”  It is quite enough to prove that they did it.  Or when there is no natural division at all in a cause, and when it is a simple question that is under discussion, though that is a thing which cannot be of frequent occurrence, still we must use careful arrangement.  And these other precepts also, with respect to the division of subjects which have no such great connexion with the practice of orators, precepts which come into use in treatises in philosophy, from which we have transferred, hither those which appeared to be suitable to our purpose, of which we found nothing in the other arts.  And in all these precepts about the division of our subjects, it will throughout our whole speech be found that every portion of them must be discussed in the same order as that in which it has been originally stated, and then, when everything has been properly explained, let the whole be summed up, and summed up so that nothing be introduced subsequently besides the conclusion.  The old man in the Andria of Terence arranges briefly and conveniently the subjects with which he wishes his freedman to become acquainted—­