Kant: Answering 'What Is Enlightenment?'

In December 1784 the philosopher Immanuel Kant of Königsberg published an essay in the Berlinische Monatsschrift answering a question a pastor had raised in a footnote: what is enlightenment? Kant's answer became the most famous definition of the movement: enlightenment is humanity's emergence from its self-incurred immaturity, the inability to use one's own understanding without another's guidance. The cause, he said, is not lack of intelligence but lack of courage, so its motto is 'Sapere aude', dare to know.

Kant distinguished the 'public use of reason', which scholars should exercise freely in writing for the reading world, from the 'private use' in an official post, where obedience may be required. He praised Frederick II for allowing people to 'argue as much as you like, but obey'. Kant said he lived in an age of enlightenment, not an enlightened age. Critics note the essay's caution about political freedom, while admirers see it as a lasting call to independent thought.