XIII And of that there are five kinds which have been separated from statements of cases.  For when the language of the writing appears to be at variance with the intention of the writer, then two laws or more seem to differ from one another, and then, too, that which has been written appears to signify two things or more.  Then also, from that which is written, something else appears to be discovered also, which is not written, and also the effect of the expressions used is inquired into, as if it were in the definitive statement of the case, in which it has been placed.  Wherefore, the first kind is that concerning the written document and the intention of it; the second arises from the laws which are contrary to one another, the third is ambiguous, the fourth is argumentative, the fifth we call definitive.

But reason applies when the whole of the inquiry does not turn on the writing, but on some arguing concerning the writing.  But, then, when the kind of argument has been duly considered, and when the statement of the case has been fully understood; when you have become aware whether it is simple or complex, and when you have ascertained whether the question turns on the letter of the writing or on general reasoning; then it is necessary to see what is the question, what is the reasoning, what is the system of examining into the excuses alleged, what means there are of establishing one’s own allegations; and all these topics must be derived from the original statement of the case.  What I call “the question” is the dispute which arises from the conflict of the two statements in this way.  “You have not done this lawfully;” “I have done it lawfully.”  And this is the conflict of arguments, and on this the statement of the case hinges.  It arises, therefore, from that kind of dispute which we call “the question,” in this way:—­“Whether he did so and so lawfully.”  The reasoning is that which embraces the whole cause; and if that be taken away, then there is no dispute remaining behind in the cause.  In this way, in order that for the sake of explaining myself more clearly, I may content myself with an easy and often quoted instance.  If Orestes be accused of matricide, unless he says this, “I did it rightfully, for she had murdered my father,” he has no defence at all.  And if his defence be taken away, then all dispute is taken away also.  The principle of his argument then is that she murdered Agamemnon.  The examination of this defence is then a dispute which arises out of the attempts to invalidate or to establish this argument.  For the argument itself may be considered sufficiently explained, since we dwelt upon it a little while ago.  “For she,” says he, “had murdered my father.”  “But,” says the adversary, “for all that it was not right for your mother to be put to death by you who were her son; for her act might have been punished without your being guilty of wickedness.”

XIV.  From this mode of bringing forward evidence, arises that last kind of dispute which we call the judication, or examination of the excuses alleged.  And that is of this kind:  whether it was right that his mother should be put to death by Orestes, because she had put to death Orestes’s father?