If memoranda
 have the same force and authority, and are arranged with the same care as accounts,
 where is the need of making an account-book? of making out careful lists? of keeping a
 regular order? of making a permanent record of old writings? But if we have adopted the
 custom of making account-books, because we put no trust in flying memoranda, shall that
 which, by all individuals, is considered unimportant and not to be relied on, be
 considered important and holy before a judge? Why is
 it that we write down memoranda carelessly, that we make up account-books carefully? For
 what reason? Because the one is to last a month, the other for ever; these are
 immediately expunged those are religiously preserved; these embrace the recollection of
 a short time, those pledge the good faith and honesty of a man for ever; these are
 thrown away, those are arranged in order. Therefore, no one ever produced memoranda at a
 trial; men do produce accounts, and read entries in books. 
 
 You, O Caius Piso, a man of the greatest good faith, and virtue, and dignity, and
 authority, would not venture to demand money on the strength of memoranda. I need not say any more about matters in which the custom is so
 notorious; but I ask you this, which is very material to the question, How long ago is
 it, O Fannius, that you made this entry in your memoranda? He blushes; he does not know
 what to answer; he is at a loss for anything to invent off-hand. “It is two
 months ago,” you will say; yet it ought to have been copied into the
 account-book of money received and paid. “It is more than six
 months.” Why then is it left so long in the memorandum-book? What if it is
 more than three years ago? How is it that, when every one else who makes up
 account-books transfers his accounts every month almost into his books you allow this
 sum to remain among your memoranda more than three years? Have you all other sums of money received and expended regularly
 entered, or not? If not, how is it that you make up your books? If you have, how is it
 that, when you were entering all other items in regular order, you leave this sum, which
 was one of the greatest of all in amount, for more than three years in your memoranda?
 “You did not like it to be known that Roscius was in your debt.” Why
 did you put it down at all? “You were asked not to enter it.” Why
 did you put it down in your memoranda? But, although I think this is strong enough, yet
 I cannot satisfy myself unless I get evidence from Caius Fannius himself that this money
 is not owed to him. It is a great thing which I am attempting; it is a difficult thing
 which I am undertaking; yet I will agree that Roscius shall not gain the verdict unless
 he has the same man both for his adversary and for his witness. A definite sum of money was owed to you, which is now sought to be recovered at law;
 and security for a legitimate portion of it has been given. In this case, if you have
 demanded one sesterce more than is owed to you, you have lost your cause; because trial
 before a judge is one thing, arbitration is another. Professor
 Long's explanation of the difference here laid down is little more than a translation
 of and comment on this passage. He says, “The following is the distinction
 between arbitrium and judicium according to Cicero ( Pro Rosc. Com.
 4 ). In a judicium the demand was of a certain or
 definite amount, pecuniae certae ).; in an arbitrium the amount was not determined ( incertae .) In a judicium the plaintiff
 obtained all that he claimed or nothing, as the words of the formula show,
 “ si paret H. S. 1000 dari
 oportere. ” (Compare Gaius, iv.
 50. ) The corresponding words in the formula arbitraria were
 “ Quantum aequius melius, id dari ”;
 and their equivalents were “ ex fide bona; ut inter bonos
 bene agier. ” (Top. 17)... If the matter was brought before a
 judex , properly so called, the judicium was constituted with a poena , that
 is per sponsionem ; there was no poena when an arbiter was demanded, and the proceeding was by the formula
 arbitraria . The proceeding by the sponsio then was the strict one, “ Angustissima formula sponsionis ,” ( Cic. pro Rosc. Com. 14 ); that of the arbitrium 
 was ex fide bona , and the arbiter, though he was bound by
 the instructions of the formula, was allowed a greater latitude by its terms. The
 engagement between the parties who accepted an arbiter, by which they bound themselves
 to abide by his arbitrium , was compromissum . ( Pro Rosc. Com. 40 ) But
 this term was also employed, as it appears, to express the engagement by which parties
 agreed to settle their differences by arbitration, without the intervention of the
 praetor . Smith, Dict. Ant. v. 530 v. Judex . Trial before a judge is about a definite sum of money;
 arbitration about one which is not determined. We come before a judge so as either to
 gain the whole suit or to lose it; we go before an arbiter on the understanding that we
 may not get all we asked, and on the other hand may not get nothing.