XXXI.  But in corroborative arguments of the most important character, those points must also be established which can be opposed to the defence, being derived either from the letter of the law, or of a will, or from the language of a judicial decision, or of a stipulation, or of a covenant.  And even this kind has no connexion with those causes which depend upon conjecture.  For when an action is denied altogether, it cannot be impeached by reference to the letter of the law.  It does not even come under definition, as to the character of the letter of the law itself.  For although some expression or other is to be defined by reference to the letter of the law, so as to be sure what meaning it has:  as when the question arises out of a will, what is meant by provisions, or out of the covenant of a lease, what are moveables or fixtures; then it is not the fact of there being written documents, but the interpretation of what is written, that gives rise to controversy.  But when many things may be implied by one expression, on account of the ambiguity of some word or words, so that he who is speaking on the other side may be allowed to draw the meaning of what is written as is advantageous to him, or in fact, as he pleases; or, if the document be not drawn up in ambiguous language, he may either deduce the wish and intention of the writer from the words, or else say that he can defend what has been done by a document which is perfectly different relating to the same facts; then a dispute arises from a comparison of the two written documents; so that the writings being ambiguous, it is a question which is most strongly implied; and in a comparison between the letter and the spirit of the documents an argument is adduced to show which the judge is the most bound to be guided by; or in documents of a wholly contradictory nature, which is the most to be approved.

But when the point in dispute is once established, then the orator ought to keep in view, what is to be proved by all the arguments derived from the different topics for discovering arguments.  And although it is quite sufficient for him who sees what is concealed in each topic, and who has all those topics, as a kind of treasury of arguments, at his fingers’ ends; still we will touch upon those which are peculiar to certain causes.

XXXII.  In conjecture, then, when the person on his trial takes refuge in denial of the fact, these are the two first things for the accuser to consider, (I say accuser, meaning every kind of plaintiff or commencer of an action; for even without any accuser, in the strict sense of the word, these same kinds of controversies may frequently arise;) however, these are his first points for consideration, the cause and the event.  When I say the cause, I mean the reason for doing a thing.  When I say the event, I mean that which was done.  And this same division of cases was made just now, when speaking of the topics of persuasion.  For the rules which were given