Ambiguity: uncertainty, lack of absolute proof
“Full proof” could lead to any sentence, but in the 17th century, proof would have been hard to obtain. Their definition of full proof, however, was ambiguous: the testimony of 2 irreproachable witnesses could count as full proof. Confessions, too, were taken as truth. Officially, a confession was ambiguous, but people took it as the most important proof that could be offered. Confessions were not always completely voluntary; torture was “a great means used by classical criminal law” that was later repeated and accepted as spontaneous and solid evidence.
Visibility: extent that an event is open and observable to the public
The role of the public in executions is also ambiguous because public outcry has been cited as a reason for the end of public executions and torture but here, Foucault says that when the guillotine was introduced to France, the crowd cried out that they wanted their gallows back.
Paradox: a situation with no obvious solution
Torture was used as both a punishment and means of getting a confession. This does not make sense, because the accused is punished before his guilt is certain. This torture was a kind of theater and also displayed the sovereignty of the law. Because the law was sovereign, the methods of achieving confessions were not questioned. Punishment and trial were wrapped up together in a “theatre of hell” and the eternal.