Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
He who produces a voluntary witness is in a
For the opposing counsel have a way of making a witness lose his head or of leading him into some trap; and once a witness trips, he does more harm to his own side than he would have done good, had he retained his composure and presence of mind. The advocate must therefore put his witnesses through their paces thoroughly in private before they appear in court and must test them by a variety of questions such as may well be put to them by his opponent. The result will be that they will not contradict themselves or, if they do make some slip, can be set upon their feet again by a timely question from the advocate who produces them.
Still, even in the case of witnesses whose evidence is consistent, we must be on our guard against treachery. For such witnesses are often put up by one's opponent and, after promising to say everything that will help our case, give answers of exactly the opposite character and carry more weight by the admission of facts which tell against us than they would have done had they disproved them.
We must therefore discover what motives they have for doing our opponent a hurt, and the fact that they were once his enemies will not suffice our purpose: we must find out whether they have ceased to be ill-disposed to him or whether they desire by means of their evidence to effect a reconciliation with him, in order to assure ourselves that they have not been bribed or repented of
For experience shows that they are more likely to repent of their purpose, their promises are less to be relied on, and, if they do keep their promise, their evidence is easier to refute.
Witnesses appearing in answer to a subpoena may be divided into two classes: those who desire to harm the accused, and those who do not. The accuser sometimes is aware of their disposition, sometimes unaware. For the moment let us assume that he is aware of their disposition, although I must point out that in either case the utmost skill is required in their examination.
For if an advocate is producing a witness who is desirous of harming the accused, he must avoid letting this desire become apparent, and must not at once proceed to question him on the point at issue. On the contrary this point must be approached by a circuitous route in such a manner as to make it seem that the statement which the witness is really desirous of making has been forced from him. Again lie should not press the witness too much, for fear he should impair his credit by the glibness with which lie answers every question, but should draw from him just so much as may seem reasonable to elicit from a single witness.