The Complete Aristotle (eng.)

witnesses, for the credit to
be attached to contracts depends upon the character of those who
have signed them or have the custody of them. The contract being
once admitted genuine, we must insist on its importance, if it
supports our case. We may argue that a contract is a law, though of
a special and limited kind; and that, while contracts do not of
course make the law binding, the law does make any lawful contract
binding, and that the law itself as a whole is a of contract, so
that any one who disregards or repudiates any contract is
repudiating the law itself. Further, most business relations-those,
namely, that are voluntary-are regulated by contracts, and if these
lose their binding force, human intercourse ceases to exist. We
need not go very deep to discover the other appropriate arguments
of this kind. If, however, the contract tells against us and for
our opponents, in the first place those arguments are suitable
which we can use to fight a law that tells against us. We do not
regard ourselves as bound to observe a bad law which it was a
mistake ever to pass: and it is ridiculous to suppose that we are
bound to observe a bad and mistaken contract. Again, we may argue
that the duty of the judge as umpire is to decide what is just, and
therefore he must ask where justice lies, and not what this or that
document means. And that it is impossible to pervert justice by
fraud or by force, since it is founded on nature, but a party to a
contract may be the victim of either fraud or force. Moreover, we
must see if the contract contravenes either universal law or any
written law of our own or another country; and also if it
contradicts any other previous or subsequent contract; arguing that
the subsequent is the binding contract, or else that the previous
one was right and the subsequent one fraudulent-whichever way suits
us. Further, we must consider the question of utility, noting
whether the contract is against the interest of the judges or not;
and so on-these arguments are as obvious as the others.
    Examination by torture is one form of evidence, to which great
weight is often attached because it is in a sense compulsory. Here
again it is not hard to point out the available grounds for
magnifying its value, if it happens to tell in our favour, and
arguing that it is the only form of evidence that is infallible;
or, on the other hand, for refuting it if it tells against us and
for our opponent, when we may say what is true of torture of every
kind alike, that people under its compulsion tell lies quite as
often as they tell the truth, sometimes persistently refusing to
tell the truth, sometimes recklessly making a false charge in order
to be let off sooner. We ought to be able to quote cases, familiar
to the judges, in which this sort of thing has actually happened.
[We must say that evidence under torture is not trustworthy, the
fact being that many men whether thick-witted, tough-skinned, or
stout of heart endure their ordeal nobly, while cowards and timid
men are full of boldness till they see the ordeal of these others:
so that no trust can be placed in evidence under torture.]
    In regard to oaths, a fourfold division can be made. A man may
either both offer and accept an oath, or neither, or one without
the other-that is, he may offer an oath but not accept one, or
accept an oath but not offer one. There is also the situation that
arises when an oath has already been sworn either by himself or by
his opponent.
    If you refuse to offer an oath, you may argue that men do not
hesitate to perjure themselves; and that if your opponent does
swear, you lose your money, whereas, if he does not, you think the
judges will decide against him; and that the risk of an
unfavourable verdict is prefer, able, since you trust the judges
and do not trust him.
    If you refuse to accept an oath, you may argue that an oath is
always paid for; that you would of course have taken it if you had
been a rascal, since if you are a rascal you had better make
something by it, and you would in that case have to swear in order
to succeed. Thus your refusal, you argue, must be due to high
principle, not to fear of perjury: and you may aptly quote the
saying of Xenophanes,
‘Tis not fair that he who fears not God
should challenge him who doth.
    It is as if a strong man were to challenge a weakling to strike,
or be struck by, him.
    If you agree to accept an oath, you may argue that you trust
yourself but not your opponent; and that (to invert