1. To begin with it may be noted that the division laid down by Aristotle Rhet. i. ii. 2. has met with almost universal approval. It is to the effect that there are some proofs adopted by the orator which lie outside the art of speaking, and others which he himself deduces or, if I may use the term, begets out of his case. The former therefore have been styled ἄτεχνοι or inartificial proofs, the latter ἔντεχνοι or artificial.

To the first class belong decisions of previous courts, rumours, evidence extracted by torture, documents, oaths, and witnesses, for it is with these that the majority of forensic arguments are concerned. But though in themselves they involve no art, all the powers of eloquence are as a rule required to disparage or refute them. Consequently in my opinion those who would eliminate the whole of this class of proof from their rules of oratory, deserve the strongest condemnation.

It is not, however, my intention to embrace all that can be said for or against these views. I do not for instance propose to lay down rules for commonplaces, a task requiring infinite detail, but merely to sketch out the general lines and method to be followed by the orator. The method once indicated, it is for the individual orator not merely to employ his powers on its application, but on the invention of similar methods as the circumstances of the case may demand. For it is impossible to deal with every kind of case, even if we confine ourselves to those which have actually occurred in the past without considering those which may occur in the future.

As regards decisions in previous courts, these fall under three heads. First, we have matters on which judgment has been given at some time or other in cases of a similar nature: these are, however, more correctly termed precedents, as for instance where a father's will has been annulled or confirmed in opposition to his sons. Secondly, there are judgments concerned with the case itself; it is from these that the name praeiudicium is derived: as examples I may cite those passed against Oppianicus pro Cluent. xvii. sqq. or by the senate against Milo. pro Mil. v. Thirdly, there are judgments passed on the actual case, as for example in cases where the accused has been deported, Banished persons who have been accused afresh after their restoration. or where renewed application is made for the recognition of an individual as a free man, When a slave claimed his liberty by assertio through a representative known as assertor, his case was not disposed of once and for all by a first failure, but the claim might be presented anew. or in portions of cases tried in the centumviral court which come before two different panels of judges. The meaning is not clear. The Latin suggests that portions of a case might be tried by two panels sitting separately, while the case as a whole was tried by the two panels sitting conjointly. The hasta (spear) was the symbol of the centumviral court. cp. XI. i. 78.

Such previous decisions are as a rule confirmed in two ways: by the authority of those who gave the decision and by the likeness between the two cases. As for their reversal, this can rarely be obtained by denouncing the judges, unless they have been guilty of obvious error. For each of those who are trying the case wishes the decision given by another to stand, since he too has to give judgment and is reluctant to create a precedent that may recoil upon himself.