Today, the joke is on me. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

Jerome Berryman offers a disquieting idea in his book, Godly Play. It has to do with humor and truth-seeking. He points to conflicting ways the Medieval Church viewed humor.

St. Thomas Aquinas said we should play and we should laugh. We live in an imperfect world. We might as well laugh at ourselves and at the imperfection around us. Still, he was cautious. He warned us to thread our way between merriment and ridicule.

But some monastic orders warned that humor harbors another danger, more grave than ridicule. That danger rises as we thread our way through true and false -- through right and wrong. All humor plays on double meaning -- on the sudden shift of reality. The joke is sprung when something turns into something else.

So, it would seem, the truth-seeker should distrust humor -- whether he's a 14th-century Benedictine monk or a 20th-century scientist. Words are the house where humor lives. And wordplay means saying two things at once. It means juggling with the truth.

That dilemma weighs in my own life. I write fairly simply and directly. I speak to you in 6th or 7th-grade prose. I work like a Benedictine monk at being unambiguous. Yet, when I go back to old scripts, I'm appalled by what I've done.

My scripts are a diary of my inner life as much as they're stories about creative people. I don't mean them to be, but words flow from unconscious corners of my mind. Every piece I write comes out as two documents, not just one. How can anything so filled with double meanings be truthful!

I might well despair of truth-telling. Then I see the joke is really on me. I've bought into a false notion of truth -- an either-or notion that's just as vain as the man who won't laugh at himself.

Modern physicists have kicked the struts from under the old positive-definite universe. Mathematicians have shown us we can never close a logical system upon itself. Our knowing is, and will remain, flawed and incomplete. Knowledge will always contain double meanings. One more surprise lurks in anything we think we know.

Learning harbors surprise, and surprise is delight. Surprise is laughter. New meanings bubble within any human knowledge. So, in the end, learning is delight after all. Laughter is the natural reward of mental fight because the world always holds things we did not see -- the first time we looked.

I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.

(Theme music)

Berryman, J.W., Godly Play. New York, Harper Collins Pubs., 1991.