Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
With regard to oaths, [*]( An oath might be taken by one of the parties as an alternative to evidence. In court such an oath might be taken only on the proposal of the adversary; the litigant might not swear on his own initiative, although an oath might be taken voluntarily before the case came into court. The matter of the oath rested with the profferer, and the taking of such a proffered oath meant victory for the swearer. ) parties either offer to take an oath themselves, or refuse to accept the oath of their opponent, demand that their opponent should take an oath or refuse to comply with a similar demand when proffered to themselves. To offer to take an oath unconditionally without demanding that one's opponent should likewise take an oath is as a rule a sign of bad faith.
If, however, anyone should take this course, he will defend his action by appealing to the blamelessness of his life
The man who refuses to accept his opponent's offer to take an oath, will allege that the inequality of their respective conditions are not the same for both parties and will point out that many persons are not in the least afraid of committing perjury, even philosophers having been found to deny that the gods intervene in human affairs; and further that he who is ready to take an oath without being asked to do so, is really proposing to pass sentence on his own case and to show what an easy and trivial thing he thinks the oath which he offers to take.
On the other hand the man who proposes to put his opponent on oath appears to act with moderation, since he is making his adversary a judge in his own case, while he frees the actual judge from the burden of coming to a decision, since the latter would assuredly prefer to rest on another man's oath than on his own.
This fact makes the refusal to take an oath all the more difficult, unless indeed the affair in question be of such a nature that it cannot be supposed that the facts are known to the person asked to take the oath. Failing this excuse, there