Kant begins his essay by defining enlightenment as humanity’s emergence from immaturity. Immaturity is the inability to think without external help. Such immaturity is self-imposed, as its cause lies not in a lack of capacity, but in fear. He coins a motto for the Enlightenment: “Sapere aude!” (Latin for "dare to know") which he glosses as, “Have the courage to use your own understanding!” Laziness and cowardice are the two major obstacles to enlightenment. Kant claims that while people are naturally endowed with the capacity for intellectual maturity, they prefer the ease of being led. People rely on authorities to think and make decisions, making it easy for societal guardians to control and exploit them.
After defining enlightenment and mentioning its barriers, Kant goes on to suggest possible paths to achieving it. Kant recognizes the difficulty of freeing oneself from immaturity through personal effort. He also dismisses a rebellion against the guardians, as this only ends oppression temporarily. He suggests that real enlightenment arises from a collective effort, and it happens slowly. To achieve enlightenment, nothing is needed besides freedom. Once society is granted freedom, the public will enlighten itself. Initially, a few individual pioneers will come to think independently, then they will spark enlightenment among the rest of the society.
Kant finetunes his discussion of freedom by distinguishing between the public and private uses of reason. The public use of reason refers to people’s free expression of their opinions in public, in writing. The private use of reason relates to people’s specific social roles, and particularly, the performance of their occupational duties. He argues that the public use of reason should be given complete freedom, allowing citizens to debate and argue on all social matters, whereas the private use of reason should be restricted to maintain public order. For instance, while a soldier must obey orders, he should be able to question them in writing addressed to the general public; he questions not in his capacity as a soldier, but as a “scholar.” Enlightenment, as Kant sees it, is an intrinsic part of human progress. Any attempts to hinder enlightenment violate fundamental human rights.
Kant believes that the society of his time is an “age of enlightenment” but not an “enlightened age.” This means that the restraints on free thinking are slowly being lifted, but not entirely. He approves of enlightened monarchs such as Frederick the Great of Prussia, who grants religious freedom to his subjects. An enlightened ruler, in Kant’s view, doesn't impose religious beliefs on his people. Instead, he allows freedom of religion and speech. Only such a ruler can lead his people out of immaturity. When the ruler permits freedom in all areas, including art, science, and religion, people can naturally come out of barbarism themselves.
Kant concludes by emphasizing the urgency of religious freedom. This is because authorities are less interested in controlling thoughts in areas like arts and sciences. He warns that restrictions on religious freedom are the most harmful of all. An enlightened ruler sees the value of intellectual freedom. Such a ruler recognizes that freedom of speech threatens neither society nor the ruler’s sovereignty. For enlightenment to spread, a ruler must be both enlightened, allowing freedom of speech, and at the same time equipped to maintain order with a strong army. The spirit of this kind of leadership is exemplified by the motto “Argue as much as you like, and about what you like, but obey!” Eventually, the influence of enlightenment will extend to governmental systems, reshaping the social sphere, and leading to a state that respects the autonomy of its citizens.
