On the 17th of February in the year 1600, the Dominican Friar, Giordano Bruno, was burned, hanging naked and upside down, at a stake in a central Roman market square. His ashes were thrown into the Tiber, and all of his works were placed on the Index Librorum Prohibitorum shortly afterwards.
His ‘crime’ was heresy, that is, refusal to accept the authority of the Church as the one and only basis of knowledge. The Church taught that the stars were part of a celestial sphere, all at the same fixed distance from the immobile Earth at the center of the sphere. Its diurnal rotation had been gifted upon it by God. Bruno, by contrast, had publicly embraced the recent Copernican heliocentric model. Bruno suggested in addition that the stars were distant suns surrounded by their own planets that might foster life of their own. He also proposed an infinite universe that had no centre.
These and other heresies were at odds with the Church’s teaching that humankind and the Earth stood at the centre of God’s creation. After a long trial by the Inquisition, in the same room in which Galileo was later to be tried, Bruno was condemned to death. He is reported to have responded to his judges, "Perhaps you pronounce this sentence against me with greater fear than I receive it”. He was one of many thousand heretics executed by the Inquisition; some say 30,000, and others put it at 300,000.
The dispute was not about science or religion; it was about authority. The Church told people what to believe, and it was heresy to think otherwise, or to suppose that people could learn and discover things by themselves. The Church of his day was not the only body to think and act in this way. In more recent times totalitarian governments have punished dissident thinkers by imprisonment and execution. The Soviet and Chinese authorities killed many millions more than did the Inquisition.
At issue is the freedom to think differently, and to express those thoughts freely. The rule, summed up by John Stuart Mill, should be that people shall be free to express dissident or controversial views, however upsetting and disquieting they may be, provided they do not incite people to commit acts of physical violence. Some of today’s campus bodies hold that inquiring minds, such as that of Bruno, should be silenced. They have more in common with the Inquisition than they would like to suppose.