In October 1794, Kant received a letter from the Prussian king: he was forbidden from making further public statements on the subject of religion under threat of punishment.. What had Kant done?
Under Friedrich II, the Enlightenment thinkers could still write freely about religion. His successor, Friedrich Wilhelm II, however, tightened state regulations. At that time, Kant, in his writings on religion, questioned the significance of ecclesiastical commandments. In the end, Kant was fortunate: the king died only a few years later, and he could publish freely again. Yet the incident shows how endangered Enlightenment and freedom of opinion always remain.