The 17th-century philosopher, John Locke, is often described as the father of modern liberalism. Now a recently discovered manuscript titled ‘Reasons for tolerateing Papists equally with others’ (1667-8) suggests that he was actually more liberal and tolerant than generally believed.

The text had long lied unnoticed in archives until it was uncovered by Locke scholar JC Walmsley. Contrary to the previously held consensus — that Locke never countenanced tolerating Catholics — this hitherto unknown document indicated that he was actually open to the idea, and explored the arguments for it. In the contemporary era, it is difficult to grasp the full significance of advocating the toleration of people holding different religious beliefs. Today, religious freedom and tolerance of competing beliefs are seen as foundational values of Western societies. However, in historical terms, tolerance is a very recent cultural and moral ideal. Until the 17th century, the toleration of different religions, opinions and beliefs was even interpreted as a form of moral cowardice, if not a symptom of heresy. As late as 1691, the French theologian Jacques-Bénigne Bossuet insisted that Catholicism was the least tolerant of all religions. He declared that: ‘I have the right to persecute you because I am right and you are wrong.’

It was in the 17th century that attitudes towards tolerating competing ideas and religions began to change. This was an era in which Europe was overwhelmed by bitter religious conflicts, which frequently resulted in bloody civil wars. In such circumstances, calls for tolerance were influenced by the pragmatic calculation that without a measure of religious toleration, endemic violence and bloodshed could not be avoided. This was the moment when a significant minority of Europeans recognised that tolerance was a prerequisite for their society’s survival. Pragmatic moves towards toleration coexisted with the growing influence of secularism and rationality. These sentiments fostered a scepticism towards religious dogmatism and intolerance. It was in this historical moment that liberalism began to emerge as a credible intellectual force. Philosophers such Pierre Bayle and Baruch Spinoza personified this new tolerant trend. John Locke went a step further, and advanced a coherent philosophical argument for adopting tolerance as a guide to public life. His A Letter Concerning Toleration (1689) can be interpreted as one of the founding documents of what would become modern liberalism.

The principle aim of Locke was to protect religious belief from state coercion. His advocacy of toleration was a call for restraining political authorities from interfering with the workings of individual conscience and lifestyles. Locke claimed that religious beliefs, which are held in people’s heads or hearts, are not appropriate objects of state control. He took the view that the coercive indoctrination of belief by the state does not lead to genuine conviction, and that the very pursuit of such a policy calls into question the rationality of political authority. His call for the toleration of a diversity of religious views was also influenced by a belief that truth cannot be imposed from without, that it requires an internal quest for answers. Though Locke took an important step towards advocating the tolerance of different religious beliefs, he was reluctant to extend this principle to Catholics. In the context of bitter religious rivalry in Protestant England, Catholics were often portrayed as agents of a rival foreign power. But Locke’s non-toleration of Catholics was justified on the grounds of political expediency rather than as a matter of religious necessity. Catholics were not to be discriminated against on religious grounds, but on political grounds. Locke regarded them as a threat to government: Catholics could not be protected because they allegedly owed allegiance to a foreign power.

Now, with the discovery of ‘Reasons for tolerateing Papists equally with others’, we know that even amid the religious conflict of the 17th century, Locke actually considered extending toleration to Catholics. It seems that Locke was even more ahead of his time than is generally supposed. It is thanks to a relatively small number of open-minded and genuinely liberal thinkers like Locke that the values of tolerance and freedom of expression have gained influence over the human imagination. Over the centuries, religious tolerance has expanded to allow the free expression of opinions, beliefs and behaviour associated with the exercise of individual conscience. Indeed, tolerance is intimately connected to the freedom of belief and conscience. The ideal of tolerance demands that we accept the right of people to live according to their beliefs and opinions, even when they are antithetical to our own.

The discovery of ‘Reasons for tolerateing Papists equally with others’ should inspire us to take tolerance seriously. Tolerance faces constant challenge in Western societies today. Speech codes and linguistic policing by governmental and non-governmental institutions threaten freedom of speech. Even freedom of belief and freedom of conscience are contested by attempts to pathologise, if not criminalise, people’s inner thoughts. In universities in the United States, newly arrived undergraduates are sent to workshops that instruct them to be ‘aware’ of various issues, which is a roundabout way of lecturing them about what to think. Tolerance is far too precious an ideal to abandon in the face of those who want to dictate what we can say and how we should think. We are in danger of forgetting what tolerance, an intimate companion of liberty and freedom, actually means. Without tolerance, we cannot be free; we cannot live with one another in relative peace; we cannot follow and act on our conscience; we cannot exercise our moral autonomy, nor pursue our own road towards seeking the truth. That is why we must uphold the spirit of toleration, pioneered by the liberal thinkers of the 17th century.