To understand what Bloom means, consider this dialogue (based loosely on a real-life exchange) between a high-school teacher and her student Elizabeth:

Teacher: Welcome, students. This is the first day of class, and so I want to lay down some ground rules. First, since no one has the truth, you should be open-minded to the opinions of your fellow students. Second . . . Elizabeth, do you have a question?

Elizabeth: Yes, I do. If nobody has the truth, isn't that a good reason for me not to listen to my fellow students? After all, if nobody has the truth, why should I waste my time listening to other people and their opinions? What's the point? Only if somebody has the truth does it make sense to be open-minded. Don't you agree?

Teacher: No, I don't. Are you claiming to know the truth? Isn't that a bit arrogant and dogmatic?

Elizabeth: Not at all. Rather, I think it's dogmatic, as well as arrogant, to assert that no single person on earth knows the truth. After all, have you met every person in the world and quizzed them exhaustively? If not, how can you make such a claim? Also, I believe it's actually the opposite of arrogance to say that I will alter my opinions to fit the truth whenever and wherever I find it. And if I happen to think that I have good reason to believe I do know the truth and would like to share it with you, why wouldn't you listen to me? Why would you automatically discredit my opinion before it is even uttered? I thought we were supposed to listen to everyone's opinion.

Teacher: This should prove to be an interesting semester.

Another student: (blurts out) Ain't that the truth. (the students laugh)

Francis J. Beckwith