But those laws which are unwritten, owe their influence either to custom or to some agreement between, and as it were to the common consent of men.  And indeed it is in some degree prescribed to us by the laws of nature, that we are to uphold our customs and laws.  And since the foundations of equity have been briefly explained in this manner, we ought to meditate carefully, with reference to causes of this kind, on what is to be said in our speeches about nature, and laws, and the customs of our ancestors, and the repelling of injuries, and revenge, and every portion of human rights.  If a man has done anything unintentionally, or through necessity, or by accident, which men would not be excused for doing if they did it of their own accord and intentionally, by way of deprecating punishment for the action he should implore pardon and indulgence, founding his petition on many topics of equity.  I have now explained as well as I could every kind of controversy, unless there is anything besides which you wish to know.

XXXVIII. C.F. I wish to know that which appears to me to be the only point left,—­what is to be done when the discussion turns upon expressions in written documents.

C.P. You are right to ask:  for when that is explained I shall have discharged the whole of the task which I have undertaken.  The rules then which relate to ambiguity are common to both parties.  For each of them will urge that the signification which he himself adopts is the one suited to the wisdom of the framer of the document; each of them will urge that that sense which his adversary says is to be gathered from the ambiguous expression in the writing, is either absurd, or inexpedient, or unjust, or discreditable, or again that it is inconsistent with other written expressions, either of other men, or, if possible, of the same man.  And he will urge further that the meaning which he himself contends for is the one which would have been intended by every sensible and respectable man; and that such an one would express himself more plainly if the case were to come over again, and that the meaning which he asserts to be the proper one has nothing in it to which objection can be made, or with which any fault can be found; but that if the contrary meaning is admitted, many vices, many foolish, unjust, and inconsistent consequences must follow.  But when it appears that the writer meant one thing and wrote another, then he who relies on the letter of the law must first explain the circumstances of the case, and then recite the law; then he must press his opponent, repeat the law, reiterate it, and ask him whether he denies that that is the expression contained in the writing, or whether he denies the facts of the case.  After that he must invoke the judge to maintain the letter of the law.  When he has dwelt on this sort of corroborative argument he must amplify his case by praising the law, and attack the audacity of the man who, when he has openly