With precisely what arguments did the Vatican justify the execution of the 16th century Dominican, Giordano Bruno, burnt at the stake as a heretic in 1600 in Rome's Campo Di Fiori?
Or how did Vatican scholars justify punishing the ageing 17th century astronomer Galileo Galilei, condemned in 1632 for proposing the heresy that the Earth was not the centre of the universe but revolved around the Sun?
Very shortly, we should have precise answers to these and other questions following the Vatican's decision, announced yesterday, to open up the archives of its infamous Inquisition, making available to bona-fide scholars and researchers documents relating to the period 1542 to 1903.
Opened alongside the Inquisition archives was the infamous In- dex of Forbidden Books. They showed that even the Bible was once on the black list.
Founded in 1233 and then revamped in 1542 by Pope Paul III, the Inquisition was nothing more or less than a legal court of the church put in place for the investigation and sentencing of those Catholics formally or informally accused of heresy - holding or expressing opinions contrary to the teaching of the church.
In theory, this sounds straightforward enough. In practice, as Galileo found out, heresy came to assume some peculiar definitions. Nor did the Inquisition prove to be especially forgiving, since 360 years passed before a formal mea culpa in the case of Galileo rehabilitated him in 1992.
For seven centuries, the Inquisition functioned as more than just a doctrinal watchdog, also acting as a cross between a secret police force and a special criminal court whose real purpose was to safeguard the church from enemies without, enemies which by turns were defined as the Reformation in the 17th century, the Enlightenment in the 18th century and socialism in the 19th century.
Church commentators would argue that the Inquisition's modern-day successor, the Congregation for the Doctrine of the Faith, headed by Cardinal Josef Ratzinger from Germany, has to some extent carried on, if in a more subtle and non-violent way, the Inquisition's work. They would cite, for example, the silencing in the 1980s of the dissident Brazilian liberation theologian, Dr Leonardo Boff.