What follows if from Immanuel Kant's 1784 essay "What is 'Enlightenment'?".
Enlightenment is man's emergence from his self-imposed immaturity. Immaturity is the inability to use one's understanding without guidance from another. This immaturity is self-imposed when its cause lies not in lack of understanding, but in lack of resolve and courage to use it without guidance from another. Sapere Aude! [dare to know] "Have courage to use your own understanding!"--that is the motto of enlightenment.
Laziness and cowardice are the reasons why so great a proportion of men, long after nature has released them from alien guidance (naturaliter maiorennes), nonetheless gladly remain in lifelong immaturity, and why it is so easy for others to establish themselves as their guardians. It is so easy to be immature. If I have a book to serve as my understanding, a pastor to serve as my conscience, a physician to determine my diet for me, and so on, I need not exert myself at all. I need not think...
But would a society of pastors, perhaps a church assembly or venerable presbytery (as those among the Dutch call themselves), not be justified in binding itself by oath to a certain unalterable symbol in order to secure a constant guardianship over each of its members and through them over the people, and this for all time: I say that this is wholly impossible. Such a contract, whose intention is to preclude forever all further enlightenment of the human race, is absolutely null and void, even if it should be ratified by the supreme power, by parliaments, and by the most solemn peace treaties. One age cannot bind itself, and thus conspire, to place a succeeding one in a condition whereby it would be impossible for the later age to expand its knowledge (particularly where it is so very important), to rid itself of errors,and generally to increase its enlightenment. That would be a crime against human nature, whose essential destiny lies precisely in such progress; subsequent generations are thus completely justified in dismissing such agreements as unauthorized and criminal.
Immanuel Kant; enlightenment.