Enlightenment is man’s emergence from his self-imposed immaturity. Immaturity is the inability to use one’s own understanding without the guidance of another. This immaturity is self-imposed if its cause is not lack of understanding, but lack of resolution and courage to use it without the guidance of another. The motto of enlightenment is therefore: Sapere aude! Have the courage to use your own understanding!
Laziness and cowardice are the reasons why such a large proportion of men, even when nature has long emancipated them from alien guidance (naturaliter maiorennes), nevertheless gladly remain immature for life. For the same reasons, it is all too easy for others to set themselves up as their guardians. It is so convenient to be immature! If I have a book to have understanding in place of me, a spiritual adviser to have a conscience for me, a doctor to judge my diet for me, and so on, I need not make any efforts at all. I need not think, so long as I can pay; others will soon enough take the tiresome job over for me. The guardians who have kindly taken upon themselves the work of supervision will soon see to it that by far the largest part of mankind… should consider the step forward to maturity not only as difficult but also as highly dangerous. Having first made their domesticated animals dumb, and carefully preventing the docile creatures from daring to take a single step without the harness to which they are tied, they next show them the danger of walking alone. Now this danger is not in fact so very great, for they would eventually learn how to walk after a few falls. But an example of this kind is intimidating, and usually scares them off from further attempts.
Thus it is difficult for each separate individual to work his way out of the immaturity which has become almost second nature to him. He has even grown fond of it and is really incapable for the time being of using his own understanding, because he was never allowed to make the attempt. Dogmas and formulas, those mechanical instruments for rational use (or rather misuse) of his natural endowments, are the ball and chain of his permanent immaturity. And if anyone did throw them off, he would still be uncertain about jumping over even the narrowest of trenches, for he would be unaccustomed to free movement of this kind. Thus only a few, by cultivating their own minds, have succeeded in freeing themselves from immaturity and in continuing boldly on their way.
There is more chance of an entire public enlightening itself. This is indeed almost inevitable, if only the public concerned is left in freedom. For there will always be a few who think for themselves, even among those appointed as guardians of the common mass. Such guardians, once they have themselves thrown off the yoke of immaturity, will disseminate the spirit of rational respect for personal value and for the duty of all men to think for themselves. The remarkable thing about this is that if the public, which was previously put under this yoke by the guardians, is suitably stirred up by some of the latter who are incapable of enlightenment, it may subsequently compel the guardians themselves to remain under the yoke. For it is very harmful to propagate prejudices, because they finally avenge themselves on the very people who first encouraged them (or whose predecessors did so). Thus a public can only achieve enlightenment slowly. A revolution may well put an end to autocratic despotism and to rapacious or power-seeking oppression, but it will never produce a true reform in ways of thinking. Instead, new prejudices, like the ones they replaced, will serve as a leash to control the great unthinking mass. For enlightenment of this kind, all that is needed is freedom. And the freedom in question is the most innocuous form of all–freedom to make public use of one’s reason in all matters. But I hear on all sides the cry: Don’t argue! The officer says: Don’t argue, drill! The tax-official: Don’t argue, pay! The clergyman: Don’t argue, believe! (Only one ruler in the world says: Argue as much as you like and about whatever you like, but obey!). All this means restrictions on freedom everywhere. But which sort of restriction prevents enlightenment, and which, instead of hindering it, can actually promote it? I reply: The public use of man’s reason must always be free, and it alone can bring about enlightenment among men; the private use of reason may quite often be very narrowly restricted, however, without undue hindrance to the progress of enlightenment. But by the public use of one’s own reason I mean that use which anyone may make of it as a man of learning addressing the entire reading public…