-- John Conroy, Unspeakable Acts, Ordinary People: The Dynamics of Torture, at 27.
... I wish I knew what passage Conroy refers to here; his book is very good on modern torture in modern democracies, but he seems to've accepted some secondary source on faith here. Cf. Aristotle, Rhetoric 1.15:
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.The fact that he dwells on the arguments against torture's credibility, suggests to me that the opposite case could be assumed to be familiar to his reader. Then as now.
A passage in the Constitution of Athens does not suggest that torture is terribly reliable:
Aristogeiton was arrested, and perished later after suffering long tortures. While under the torture he accused many persons who belonged by birth to the most distinguished families and were also personal friends of the tyrants. At first the government could find no clue to the conspiracy * * *. According to the story of the popular party, Aristogeiton accused the friends of the tyrants with the deliberate intention that the latter might commit an impious act, and at the same time weaken themselves, by putting to death innocent men who were their own friends; others say that he told no falsehood, but was betraying the actual accomplices. At last, when for all his efforts he could not obtain release by death, he promised to give further information against a number of other persons; and, having induced Hippias to give him his hand to confirm his word, as soon as he had hold of it he reviled him for giving his hand to the murderer of his brother, till Hippias, in a frenzy of rage, lost control of himself and snatched out his dagger and dispatched him.I google up some references suggesting that slaves and barbarians, lacking reason, are childlike and simply tell the truth under torture, rather than lie. Where this may be found in his works, and what it implies about "reason," I cannot say.
... Conroy cites Edward Peters' book Torture, pp. 13-14, but looking at those pages via Amazon, I don't find that they support his "favoring" torture or giving it "absolute credibility." Conroy is either misremembering his source or is simply mistaken.