But should a society of clergymen, for instance an ecclesiastical assembly, be entitled to commit itself by oath to a certain unalterable doctrine in order to perpetuate an endless guardianship over each of its members and through them over the people? I answer that this is quite inconceivable. Such a contract which would be concluded in order to keep humanity forever from all further enlightenment is absolutely impossible, even should it be confirmed by the highest authority through parliaments and the most solemn peace treaties. An age cannot conclude a pact and take an oath upon it to commit the succeeding age to a situation in which it would be impossible for the latter to enlarge even its most important knowledge, to eliminate error and altogether to progress in enlightenment. Such a thing would be a crime against human nature, the original destiny of which consists in such progress. Succeeding generations are entirely justified in discarding such decisions as unauthorized and criminal. The touchstone of all this to be agreed upon as a law for people is to be found in the question whether a people could impose such a law upon itself. Now it might be possible to introduce a certain order for a definite short period as if in anticipation of a better order. This would be true if one permitted at the same time each citizen and especially the clergyman to make his criticisms in his quality as a scholar… . In the meantime, the provisional order might continue until the insight into the particular matter in hand has publicly progressed to the point where through a combination of voices (although not, perhaps, of all) a proposal may be brought to the crown. Thus those congregations would be protected which had agreed to (a changed religious institution) according to their own ideas and better understanding, without hindering those who desired to allow the old institutions to continue… .
A man may postpone for himself, but only for a short time, enlightening himself regarding what he ought to know. But to resign from such enlightenment altogether either for his own person or even more for his descendants means to violate and to trample underfoot the sacred rights of mankind. Whatever a people may not decide for themselves, a monarch may even less decide for the people, for his legislative reputation rests upon his uniting the entire people’s will in his own. If the monarch will only see to it that every true or imagined reform (of religion) fits in with the civil order, he had best let his subjects do what they consider necessary for the sake of their salvation; that is not his affair. His only concern is to prevent one subject from hindering another by force, to work according to each subject’s best ability to determine and to promote his salvation. In fact, it detracts from his majesty if he interferes in such matters and subjects to governmental supervision the writings by which his subjects seek to clarify their ideas (concerning religion). This is true whether he does it from his own highest insight, for in this case he exposes himself to the reproach: Caesar non est supra grammaticos; it is even more true when he debases his highest power to support the spiritual despotism of some tyrants in his state against the rest of his subjects.
The question may now be put: Do we live at present in an enlightened age? The answer is: No, but in an age of enlightenment. Much still prevents men from being placed in a position or even being placed into position to use their own minds securely and well in matters of religion. But we do have very definite indications that this field of endeavor is being opened up for men to work freely and reduce gradually the hindrances preventing a general enlightenment and an escape from self-caused immaturity. In this sense, this age is the age of enlightenment and the age of Frederick (the Great).
A prince should not consider it beneath him to declare that he believes it to be his duty not to prescribe anything to his subjects in matters of religion but to leave to them complete freedom in such things. In other words, a prince who refuses the conceited title of being “tolerant” is himself enlightened. He deserves to be praised by his grateful contemporaries and descendants as the man who first freed humankind of immaturity, at least as far as the government is concerned and who permitted everyone to use his own reason in all matters of conscience. Under his rule, venerable clergymen could, regardless of their official duty, set forth their opinions and views even though they differ from the accepted doctrine here and there; they could do so in the quality of scholars, freely and publicly. The same holds even more true of every other person who is not thus restricted by official duty. This spirit of freedom is spreading even outside (the country of Frederick the Great) to places where it has to struggle with the external hindrances imposed by a government which misunderstands its own position. For an example is illuminating them which shows that such freedom (public discussion) need not cause the slightest worry regarding public security and the unity of the commonwealth. Men raise themselves by and by out of backwardness if one does not purposely invent artifices to keep them down.
I have emphasized the main point of enlightenment, that is of man’s release from his self-caused immaturity, primarily in matters of religion. I have done this because our rulers have no interest in playing the guardian of their subjects in matters of arts and sciences. Furthermore immaturity in matters of religion is not only most noxious but also most dishonorable. But the point of view of a head of state who favors freedom in the arts and sciences goes even farther; for he understands that there is no danger in legislation permitting his subjects to make public use of their own reason and to submit publicly their