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 the enlightenment.
Laziness and cowardice are the reasons why so great a proportion of men, long after nature has released them from the guidance of others (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, if only I can pay: others will readily undertake the irksome work for me. The guardians who have so benevolently taken over the supervision of men have carefully seen to it that the far greatest part of them (including the entire fair sex) regard taking the step to maturity as very dangerous, not to mention difficult. Having first made their domestic livestock dumb, and having carefully made sure that these docile creatures will not take a single step without the walker to which they are harnessed, these guardians then show them the danger that threatens them, should they attempt to walk alone. Now this danger is not actually so great, for after falling a few times they would in the end certainly learn to walk; but an example of this kind makes men timid and usually frightens them out of all further attempts.
Thus, it is difficult for any individual man to work himself out of the immaturity that has all but become his nature. He has even become fond of this state and for the time being is actually incapable of using his own understanding, for no one has ever allowed him to attempt it. Rules and formulas, those mechanical aids to the rational use, or rather misuse, of his natural gifts, are the shackles of a permanent immaturity. Whoever threw them off would still make only an uncertain leap over the smallest ditch, since he is unaccustomed to this kind of free movement. Consequently, only a few have succeeded, by cultivating their own minds, in freeing themselves from immaturity and pursuing a secure course.
But that the public should enlighten itself is more likely; indeed, if it is only allowed freedom, enlightenment is almost inevitable. For even among the entrenched guardians of the great masses a few will always think for themselves, a few who, after having themselves thrown off the yoke of immaturity, will spread the spirit of a rational appreciation for both their own worth and for each person’s calling to think for himself. But it should be particularly noted that if a public that was first placed in this yoke by the guardians is suitably aroused by some of those who are altogether incapable of enlightenment, it may force the guardians themselves to remain under the yoke — so pernicious is it to instill prejudices, for they finally take revenge upon their originators, or on their descendants. Thus a public can only attain enlightenment slowly. Perhaps a revolution can overthrow autocratic despotism and profiteering or power-grabbing oppression, but it can never truly reform a manner of thinking; instead, new prejudices, just like the old ones they replace, will serve as a leash for the great unthinking mass.
Nothing is required for this enlightenment, however, except freedom; and the freedom in question is the least harmful of all, namely, the freedom to use reason publicly in all matters. [...]
— From the essay: Immanuel Kant, “What is Enlightenment?” [Original publication: “Beantwortung der Frage: Was ist Aufklärung?,” in Berlinische Monatsschrift (December, 1784), pp. 481-94]