Aristotle, Rhetoric
J. H. Freese, Ed.

[26] Torture is a kind of evidence, which appears trustworthy, because a sort of compulsion is attached to it. Nor is it difficult to see what may be said concerning it, and by what arguments, if it is in our favor, we can exaggerate its importance by asserting that it is the only true kind of evidence;
but if it is against us and in favor of our opponent, we can destroy its value by telling the truth about all kinds of torture generally; for those under compulsion are as likely to give false evidence as true, some being ready to endure everything rather than tell the truth, while others are equally ready to make false charges against others, in the hope of being sooner released from torture. It is also necessary to be able to quote actual examples of the kind with which the judges are acquainted. It may also be said that evidence given under torture is not true; for many thick-witted and thick-skinned persons, and those who are stout-hearted heroically hold out under sufferings, while the cowardly and cautious, before they see the sufferings before them, are bold enough; wherefore evidence from torture may be considered utterly untrustworthy.