According to famous German philosopher Immanuel Kant, Enlightenment refers to man’s release from his self-incurred tutelage. In other words, Kant describes Enlightenment as a man’s courage to start using his/her own reason by defeating two most important enemies of human progress; laziness and cowardice.
Kant sees Enlightenment is like a way out from immaturity, incompetence. By immaturity and incompetence he means not using our reasoning and only obeying to the authority’s rules. Kant also believes that Enlightenment is both a collective process and a personal one because all men participate in it collectively, but personal courage is also needed. Kant explains two essential conditions by which men can get away from immaturity; public and private use of reason. Kant believes that the public use of reason must always be free. A scholar must be free to make research on controversial topics, assess the government's policies. He/She is free to use reason in the public life as a free individual. However, by private use of reason he means a particular state office. In a position like this, a man should obey the orders of his/her superiors and his/her freedom can be restricted. Even if a man discovers mistakes in the working of a civil post he should continue to do the duties of his office. However, norms of the state should not be unchangeable because it would prevent men's progress. He also thinks that the freedom of reason in mostly suppressed in the area of religion.
Kant also has very negative ideas about revolution. He thinks that without having internalized new ideas, a revolution would not be successful and would bring its own prejudices. In his idea Enlightenment can be attained slowly and reform is better than revolution. Enlightenment is a long process that would encourage people to use their own reason instead of obeying in the public use of the reason. Kant's prescription for becoming an adult is in that way.
When we analyze Kant’s ideas, it is easy to see that much priority is given to reason and humans are considered as rational. He obviously believes in progress and modernization but he does not favor revolution. Instead, he thinks that humans should obey orders of their superiors when they have a civil post, mission and they can only be free in their public lives. Although he gives too much importance to reason, he is considered as a critical philosopher rather than a rationalist because he makes the criticism of Enlightenment.