You're referring to Immanuel Kant's famous essay "An Answer to the Question: What is Enlightenment?"!

Published in 1784, this essay is a cornerstone of philosophical thought, offering a concise and influential definition of Enlightenment. Here's a brief summary:

**The Problem:** In the late 18th century, Europe was grappling with the Age of Reason, a period marked by scientific discoveries, intellectual curiosity, and social upheaval. However, there were still many people who clung to traditional authority and superstition. Kant aimed to clarify what it meant to be enlightened.

**Kant's Definition:** "Enlightenment" is not simply a matter of gaining knowledge or intelligence; rather, it is the emergence from self-incurred immaturity. In other words, Enlightenment occurs when individuals take responsibility for their own thinking and decision-making, rather than relying on authority figures (e.g., monarchs, clergy) to guide them.

**Three Senses:** Kant identified three aspects of Enlightenment:

1. **Linguistic**: The ability to think critically about language, recognizing that words have meanings independent of external authorities.
2. **Moral**: The capacity to act according to one's own moral principles, rather than simply following rules imposed by others.
3. **Civic**: The willingness to engage in public discourse and participate in the governance of society, as opposed to passively accepting authority.

**Consequences:** By embracing Enlightenment, individuals:

* Develop critical thinking and problem-solving skills
* Foster autonomy and self-reliance
* Encourage innovation and progress

In essence, Kant's essay emphasizes that genuine enlightenment involves not only acquiring knowledge but also cultivating the courage to think for oneself, question traditional authorities, and contribute meaningfully to society.

As you mentioned, this essay is remarkably short (around 1,000 words), yet its implications have had a profound impact on modern thought. If you haven't already, I encourage you to read it!