Religious intolerance is almost as old as religion itself. Where belief is couched in terms of a battle of good versus evil, it may entail a sense of righteous certainty, a conviction that anyone who holds different beliefs is damnable and deserves death.
The persecution of dissenters is most likely to happen where religion has been institutionalized. Whenever this happens, persecution preserves power as well as defending doctrine. In many cases, institutionalized religion has been allied with (or even controlled by) state power. One title of the Roman emperors was pontifex maximus , ‘high priest’. The Romans tolerated a range of religions, many even joining such cults as Mithraism. But the Roman state saw the early Christians as a threat: they attracted the dispossessed, and talked seditiously about building Christ’s kingdom on Earth. Persecutions ensued, until the Roman emperors decided to adopt Christianity themselves. Now the Church became an instrument of state power, and in its turn persecuted religious minorities regarded as heretical.
Sometimes those in power have recognized that toleration, original thought, innovation and pluralism make for a happier, more prosperous society. In imperial China, three religions – Confucianism, Daoism and Buddhism – coexisted peacefully. In India in the later 16th century, Akbar, the greatest of the Mughal emperors, sought to hold together his vast empire by extending religious toleration to all his subjects, whether Hindu, Sikh or Jain, even though he himself was a Muslim. But a century later his powerful descendant Aurangzeb turned the Mughal empire into a more exclusively Muslim state, repressing the Hindu majority and fighting wars against the Sikhs, whose ninth Guru he had executed. He thus damaged the sense of imperial unity built up by Akbar, and in the century after his death in 1707 Mughal power was fatally eroded, allowing Europeans to gain a foothold on the subcontinent.
‘The emperor’s court became the home of the inquirers of the seven climes, and the assemblage of the wise of every religion and sect.’
Abul Fazl, The History of Akbar (c . 1590), pointing out the benefits of the Mughal emperor’s religious toleration
Muslim rulers in Spain had at first shown tolerance towards Jews and Christians, permitting them to practise their religions as long as they were prepared to pay higher taxes. The caliphate of Córdoba (929–1031) witnessed something of a golden age, as culture flowered and trade expanded. But toleration shrank under the Almohad dynasty in the 12th–13th centuries, and vanished after the Spanish Christians completed their Reconquista of the Iberian peninsula by seizing Granada in 1492. Jews and Muslims were forced to convert to Christianity or face expulsion, and this drove many of the most intelligent and skilled inhabitants abroad – just as when Louis XIV turned against French Protestants in 1685, and when the Nazis persecuted German Jews in the 1930s.
The Reformation launched in the early 16th century set Protestants against Catholics, and over the next two centuries Europe suffered a frenzy of persecution and conflict. The Thirty Years’ War (1618–48) killed as much as one-third of the German population, mostly through starvation and disease, as the armies of the Catholic and Protestant powers of Europe laid waste to the land. It took many generations for Germany to recover.
Religious toleration only became the norm much later across Europe, despite the urgings of the thinkers of the 18th century Enlightenment (see here ). In Britain, not until the Crown Act of 2013 could a Roman Catholic take the throne. To this day religious toleration faces threats in many nations, both from fundamentalists and from authoritarian secular states such as China.