'What is Truth?' asked Pilate, examining one of the most famous prisoners of all, and he might also have reflected on that perennial legal problem 'How do we get at it?' If Jesus had been a slave, the prefect of Judaea would have had an easy option open to him - torture followed by confession.
In the ancient world, confession rested on an unholy assumption about truth: that slaves would only confess the truth if they had been tortured.
The master of a slave was a rational creature, and could choose whether to tell or cover up the truth.
But the slave was thought of as little above a brute beast who, incapable of such subterfuge, could be forced by violence to disgorge whole what he had seen - truth, the whole truth and nothing but the truth, but only by torture.
This was the sordid back-drop to justice which orators like Cicero drew upon when they rose to address the courts of Ancient Rome.
Dr Kathryn Tempest of Roehampton University excavates the roots of one of the most powerful legal concepts of all time.
Dr Kathryn Tempest examines the roots of one of history's most powerful legal concepts.
How do you catch the truth? Pin it and preserve it like a butterfly? Make the ephemeral and hidden into something both visible and fast? The medieval versions of these questions exercised the Inquisitors of the Western church.
They were looking for new ways of getting at truth through confession which went beyond the say-so of the community, and instead entered deep into the hearts and psyches of individuals.
This was a knotty problem requiring great subtlety.
"Deep is the heart of man, and inscrutable." wrote the Dominican, Bernard Gui, 'The wise inquisitor should be careful to set his course by the replies of the witnesses, the sworn statements of accusers, the counsel of men taught by experience, the shrewdness of his own natural intelligence, and the following lists of questions' (which he went on to supply).
And yet, despite all this careful pondering, torture was resorted to again, this time, in the quest to detect and uproot heresy.
Once more the queasy relationship between truth and coercion surfaces.
Professor John Arnold of Birkbeck College, University of London, takes us into the mental world of the inquisitions.
Confession spans the spiritual and legal.
Prof John Arnold explores the Inquisition.
Now it's time to step inside the interrogation room in one of the most famous cases of all.
In the spring of 1662, in Auldearn in north east Scotland, the peasant woman, Isobel Gowdie, was interrogated for witchcraft.
Her confessions, made over a six-week period were studded with startling revelations of the fairy world, shot-through with folklore and charms and well-told anecdotes.
They have been arresting the imagination of writers and scholars and artists for hundreds of years.
They would even give birth to one of Scotland's best-known orchestral pieces: James Macmillan's 'The Confession of Isobel Gowdie'.
But if you ask a witchcraft scholar like Dr Emma Wilby of Exeter University what's so remarkable about those confessions (apart from 'everything'), it's the way Isobel's own voice seems to come through to such an extent that we can begin to disentangle her from her interrogators, that we can begin to see the alchemy behind this unique confession, and to meet Isobel herself, who appears for us through her own words read by the actor Gerda Stevenson.
Isobel Gowdie skilfully elaborated her witch confession.
Dr Emma Wilby examines why.
'This is not my defence,' said Nikolai Bukharin as The Party tried him for his life, 'this is my self-accusation'.
He then produced a confession in some ways worthy of Isobel Gowdie the witch.
It began with the standard demonology of communism - being in league with Trotsky, plotting from the very start to usurp power from Lenin.
But then it soared into the realms of global conspiracy hatched by Fascists and Zionists in league with French, Japanese and British intelligence.
Freemasons, Lawrence of Arabia and the tsarist secret police were even included in the plot.
Why? What on earth was to be gained by this farrago? Dr Iain Lauchlan of Edinburgh University explores the Moscow show trials of 1938 and asks 'Whose confession were they really?
Dr Iain Lauchlan explores the Moscow show trials.
Were they an atheist inquisition?
So why do we want confession despite its often chilling heritage? When Tiger Woods confesses to cheating on his wife, or a tearful Jade Goody confesses to bullying Shilpa Shetty in the Big Brother House, what is in it for us? Why in a society where these actions are not crimes, do we want the television interviewer or journalist to step into the inquisitor's shoes and the media to serve us up the heart of the 'wrongdoer' on a plate? Surely in a society where confession has sat at the heart of miscarriage of justice again and again, we ought to be wise to its potential for deception by now? Yet like the inquisitor Bernard Gui, even as we list the caveats of the process we are still unwilling to give it up as an instrument of truth or to look away.
Journalist and writer Andrew Brown considers the modern public role of confession.
Journalist Andrew Brown examines our insatiable appetite for celebrity confession.