Religious Toleration: From Persecution to Pluralism

On October 22, 1762, a sixty-eight-year-old Protestant merchant named Marc-Antoine Calas was tortured to death in the town hall of Toulouse. The charge was that he had murdered his own son to prevent the son’s conversion to Catholicism. The evidence was practically nonexistent. The young man, Marc-Antoine’s son, had been found dead the previous evening; he had been depressed, his family said, and may have taken his own life. But the Toulouse establishment needed a Protestant to convict, and Calas was the obvious candidate. The case was typical of its kind: a religious minority, a charge of crimes against religion, a confession extracted by torture, a verdict reached in a single day.

Voltaire, then living at Ferney on the Swiss border, got hold of the case three years later. He spent the rest of his life on it. The Calas affair made Voltaire into the most famous defender of religious toleration in Europe, and it made the cause of toleration into a cause with a body count. The rehabilitation of Calas was finally secured in 1765, by which point Voltaire had turned the case into a European scandal and had published the Traité sur la tolérance (1763), one of the founding documents of the modern defence of religious freedom. The episode is a useful place to begin an account of the Enlightenment defence of toleration, because it makes the abstract doctrine concrete: toleration is not a theoretical commitment, it is the legal protection of people whom the majority would happily destroy.

The defence of religious toleration — the principle that the state should not use force in matters of religious belief — was one of the central causes of the Enlightenment. The thinkers of the eighteenth century argued that the proper functioning of the political life required the recognition of the rights of religious minorities, and that the attempt to enforce religious uniformity by force was both futile and counterproductive. The contemporary principles of religious freedom, of the separation of church and state, and of religious pluralism are all direct descendants of the Enlightenment defence.

The background: a long history of persecution

The defence of religious toleration was developed in the context of a long history of religious conflict and persecution in early modern Europe. The Protestant Reformation of the sixteenth century shattered the religious unity of Western Europe, and the subsequent wars of religion — culminating in the Thirty Years’ War of 1618 to 1648 — were among the most destructive conflicts in European history. The wars produced a number of attempts to address the problem of religious diversity, including the Peace of Augsburg (1555), which established the principle of cuius regio, eius religio (“whose realm, his religion”), and the Peace of Westphalia (1648), which established a more comprehensive system of religious coexistence. The English Civil War of the 1640s and the Glorious Revolution of 1688 produced their own developments. The Act of Toleration of 1689, although it was limited in scope, established the principle that Protestant Dissenters should be free to worship in their own way, and the gradual extension of toleration to Catholics and Jews in the nineteenth century was one of the great achievements of modern British history.

The revocation of the Edict of Nantes in France in 1685, which led to the persecution and the emigration of hundreds of thousands of French Protestants, was one of the most notorious examples of religious persecution in the early modern period. The Huguenots who fled France — to the Dutch Republic, to the German states, to England, to the American colonies — took with them a memory of persecution that fed into the Enlightenment case for toleration. Jonathan Israel’s recent scholarship, Religious Toleration in the Atlantic World (2014), has shown the extent to which the practical experience of persecution, and the practical experience of refuge, shaped the development of the modern theory.

The major defenders

The defence of religious toleration was developed by a number of major thinkers in the sixteenth, seventeenth, and eighteenth centuries. The following are the most important.

Sebastian Castellio

Sebastian Castellio (1515–1563) was a French humanist and Protestant theologian who wrote one of the earliest systematic defences of religious toleration. His De haereticis, an sint persequendi (Whether Heretics Should Be Persecuted, 1554), written under the pseudonym Martinus Bellius, was a response to the execution of the Spanish physician Michael Servetus, who had been burned at the stake by the Protestant authorities of Geneva for his anti-Trinitarian views. Calvin, the reformer of Geneva, defended the execution. Castellio replied, in one of the most quoted sentences in the literature of toleration: “To kill a man is not to defend a doctrine, but to kill a man.” The exchange established the basic positions of the subsequent debate: the orthodox, who held that the defense of true doctrine required the suppression of false doctrine; the tolerant, who held that the suppression of false doctrine was incompatible with the proper use of reason and the proper respect for the dignity of the human person.

Jacobus Acontius

Jacobus Acontius (c. 1500 – c. 1566) was an Italian engineer, philosopher, and theologian who wrote Stratagemata Satanae (The Stratagems of Satan, 1565), one of the most important early defences of religious toleration. Acontius argued that Christian unity could not be achieved by force, and that the proper response to religious disagreement was charity and patience. The work was widely read in the late sixteenth and seventeenth centuries, and it had an important influence on the development of the early modern defence of religious toleration. The work was particularly influential in the development of the Arminian movement in the Netherlands, which developed a more tolerant version of Calvinism that was an important precursor of the Enlightenment defence.

Baruch Spinoza

Baruch Spinoza (1632–1677) developed one of the most thoroughgoing defences of religious toleration in his Tractatus Theologico-Politicus (Theological-Political Treatise, 1670). Spinoza argued that the proper function of the state was the maintenance of peace and security, not the enforcement of religious orthodoxy. The state should, therefore, tolerate all religious groups, including those with very different views from the established church. Spinoza’s argument was based on the principle that the attempt to compel belief was both futile and counterproductive. It was futile because the human mind could not be compelled to believe what it did not believe; it was counterproductive because it led to hypocrisy and to the corruption of the moral and intellectual life of the community. The argument was a powerful contribution to the development of the modern theory of religious toleration.

John Locke

John Locke (1632–1704) developed one of the most influential defences of religious toleration in his Letter Concerning Toleration (1689). Locke argued that the state had no authority to use force in matters of religious belief, and that the church was a voluntary association of believers with no right to coerce its members or non-members. Locke’s argument was based on several principles. First, the proper function of the state was the protection of the civil interests of the citizens, and the state had no competence to determine the truth of contested religious questions. Second, the church was a voluntary association of believers, and the use of force in religious matters was inconsistent with the nature of Christian community. Third, the attempt to compel belief was futile and counterproductive.

Locke’s argument was not without limits. He excluded from the scope of toleration Catholics (on the grounds that they owed allegiance to a foreign power) and atheists (on the grounds that they could not be trusted to keep their promises because they had no fear of divine retribution). These exclusions were embarrassing even at the time, and the subsequent tradition has rightly abandoned them. But it is worth noticing that they were there, and that they remind us that the original defence of toleration was a qualified defence, not an absolute one. The qualifications were the price of making toleration acceptable to a political class that was not prepared to accept the full version of the principle.

Voltaire

Voltaire (1694–1778) was the most famous defender of religious toleration in the eighteenth century, and the reason is that he turned the case for toleration into a series of moral campaigns. The Calas affair, as already noted, was the most famous. The Sirven affair (1762–1771) and the La Barre affair (1766) were the next most famous. In each case, an innocent person was tortured and killed on a charge connected to religion, and in each case, Voltaire used his pen, his European reputation, and his network of correspondents to make the case of the victim into a European cause. Voltaire’s Traité sur la tolérance (1763) was a passionate appeal for the principle that all human beings deserve equal treatment under the law, regardless of their religious beliefs. The work was widely read throughout Europe, and it had an important influence on the development of the modern principles of religious freedom and pluralism.

Pierre Bayle

Pierre Bayle (1647–1706) was the French philosopher and encyclopedist who developed the most thoroughgoing philosophical defence of religious toleration. His Philosophical Commentary on These Words of the Gospel, “Compel Them to Come In” (1686) argued that even if it could be shown that one religion was true, the use of force to impose it was still illegitimate, because sincere belief could not be compelled. Bayle’s argument was based on the principle of the freedom of conscience. The attempt to use force in matters of religious belief was, he argued, a violation of the natural rights of the individual, and it was also a violation of the proper nature of religious community. The argument was widely discussed in the late seventeenth and eighteenth centuries, and it had an important influence on the development of the modern principles of religious freedom.

The development of the modern principles

The Enlightenment defence of religious toleration was an important source of the modern principles of religious freedom, of the separation of church and state, and of religious pluralism.

The American model of religious freedom was developed in the late eighteenth century, and it was one of the great American contributions to the modern theory of religious toleration. The Virginia Statute for Religious Freedom, drafted by Thomas Jefferson and enacted in 1786, was the most important statement of the principle. The American Constitution, with its First Amendment prohibition of the establishment of religion and its protection of the free exercise of religion, was a direct expression of the Enlightenment principles. The American model has been widely imitated, and it has become a basic feature of the modern constitutional state.

The European model of religious toleration developed in a different way from the American. The European states generally maintained established churches well into the twentieth century, and the gradual extension of religious freedom to all groups was a long and difficult process. The European Convention on Human Rights (1950), with its Article 9 protection of the freedom of thought, conscience, and religion, represents the culmination of this process. The European Court of Human Rights has developed a substantial body of jurisprudence on the proper limits of religious freedom, and the contemporary European debate about the proper relationship between religious freedom and other important interests is a continuation of the Enlightenment debate about the proper foundation of religious toleration.

The international standards of religious freedom are direct descendants of the Enlightenment tradition. Article 18 of the Universal Declaration of Human Rights (1948) provides that “everyone has the right to freedom of thought, conscience and religion; this right includes freedom to change his religion or belief, and freedom, either alone or in community with others and in public or private, to manifest his religion or belief in teaching, practice, worship and observance.” The various international covenants and conventions that have been developed since 1948 — the International Covenant on Civil and Political Rights, the Declaration on the Elimination of All Forms of Intolerance and of Discrimination Based on Religion or Belief, and many others — all contain similar provisions.

The contemporary challenges

The contemporary challenges to religious toleration are different from those faced by the Enlightenment defenders, but they are no less pressing.

The challenge of pluralism: the contemporary world is more religiously diverse than ever before, and the proper response to this diversity is one of the central challenges of contemporary political life. The cities of Europe and North America contain, in many cases, religious communities that did not exist in the eighteenth century, and the constitutional traditions that were designed for a more religiously homogeneous population are being tested by the new pluralism.

The challenge of religious extremism: the rise of religious extremism in various parts of the world has made it more difficult to maintain the principles of religious toleration, and it has raised new questions about the proper limits of the modern principle. The basic commitment of the Enlightenment — to the principle that the state should not use force in matters of religious belief — is more difficult to maintain when some religious groups use their religious commitments to justify violence against the state or against other groups.

The challenge of the relationship between religion and state: the proper relationship between religious institutions and the state is a continuing subject of debate in many countries, and the contemporary debate is a continuation of the Enlightenment debate about the proper foundation of religious toleration. The French tradition of laïcité, the American tradition of separation, the British tradition of established churches with guarantees of religious freedom — these are different solutions to the same problem, and the comparative evaluation of the solutions is one of the standing questions of comparative constitutionalism.

The challenge of religious freedom and other rights: the proper balance between religious freedom and other important rights — the rights of women, the rights of LGBT people, the rights of religious minorities — is a central question of contemporary political life. The question is genuinely difficult, and the Enlightenment tradition does not, by itself, provide a complete answer. The defenders of religious freedom argue that the proper protection of religious freedom is the foundation of a liberal political order. The critics argue that the proper protection of the other rights requires the limitation of religious freedom in certain cases. The debate is not closed, and it is not going to be closed, because the question is one of the standing questions of liberal political theory.

The basic commitment of the Enlightenment — to the principle that the proper functioning of the political life requires the recognition of the rights of religious minorities, and that the attempt to enforce religious uniformity by force is both futile and counterproductive — remains a basic commitment of contemporary democratic thought. The hard question is how to honor that commitment in the conditions of the contemporary world. The Enlightenment defenders worked out the basic framework. We are still working out the details.