Philosophy for Kids: What is Untruth?

Philosopher Heidegger shares the following thought experiment:

  • We take a slip of paper and write down the truth: “Here is the chalk.” We lay this transcribed truth next to the thing, about which it is the truth. When the lecture is finished, both doors are opened, the lecture hall is aired, there is a draft and the slip of paper—let us suppose—will flutter out into the hallway. A student discovers the slip of paper on his or her way to the cafeteria, reads the statement “Here is the chalk,” and realizes that this does not hold at all. By way of the draft, the truth has become an untruth. We write on the blackboard: “Now it’s afternoon.” Now, right now, on this afternoon. After the lecture—let us suppose—the lecture hall will be locked up, so that nobody can approach the transcribed truth and secretly falsify it. Early the next morning, the janitor may enter in order to clean the blackboard. He reads the truth: “Now it’s afternoon.” And he discovers that the statement is untrue, that this professor has made a mistake. Overnight the truth has become an untruth.

Using these ideas, can you describe what “untruth” is?