The American poet Carl Sandburg used to begin his readings with this anecdote. Two sailors are marooned on an island. Each decides to write a poem. The first sailor writes, "I lost my all/In the Bay of Bengal."

The second sailor writes, "I lost my shirt/In the Bay of Bengal."

The first sailor says, "That's not a poem. It doesn't even rhyme."

The second sailor says, "It's a better poem than yours. It's real, unlike that nonsense you wrote."

Sandburg's point was that poetry is not a place for needless exaggeration, and that one of its purposes is to purify language, put it more in line with reality.

More and more, however, the language we use and hear is inflated and manipulative. I call these flights of rhetoric "fictions."

The term has a specific and layered meaning. "Fiction" is not the same as "spin," which indicates interpretation. It's not "myth," which implies a total falsehood.

Instead, fictions are somewhat true, or—as some films claim—they're "based on a true story." They contain complex cultural and historical attitudes. They try to create a view of the world. They may masquerade as fact, but they're not fact. They are, quite simply, fictional.

It's not news that linguistic assumptions permeate our society. What's news is that so many of us—possibly because we live in a visual age—aren't aware of them. Yet these fictions work on us, especially if we're oblivious to them. Fictions can prevent us from thinking clearly, critically, and creatively, for they channel our thinking in rigid ways.

If we don't realize we are surrounded by fictions, we can make dangerous mistakes. As the Confucian text suggests, language is the first thing that goes corrupt in a society.

Let's examine some fictions that underlie our world.

Take the weather report. We know the facts: The Earth is a terrarium in which wind, water, and sun combine, fairly predictably, into a pattern of seasons. Once, weather reports tended to emphasize the positive. Today's rain will pass by tomorrow night; sunshine will return the day after. The former fiction of the weather report: "Storms never last."

Post-9/11 weather reports tell us that although the rain will stop tomorrow night, a storm is brewing for next week, so stay tuned. The rhetoric: "Good weather doesn't last. A storm is always on the way."

The language becomes even more bloated during the winter, when a "monster" snowstorm is about to pounce on poor, helpless Boston.

I know simply telling New Englanders that, yes, it snows in February would take all the fun out of a coming storm. However, suggesting folks run out to buy blankets, flashlights, batteries, and canned food conjures the common fiction that "it's hell out there." Even rainstorms are sometimes accompanied by warnings of floods, high winds, and power outages. The weather hasn't changed, just the rhetoric.

Another recent fiction was borrowed from the classical world: The United States of America is an empire, more powerful than the Roman Empire, indeed, the most powerful empire of all time; it will soon rule the world unopposed. This fiction has been widely believed. But the difficulties of fighting terrorists after 9/11 and of winning a war against Iraq are indicating it may not have staying power.

Of course, fictions apply to many aspects of our lives, and many, like good stories, help us make sense out of the world. But fictions are useful for only so long.

As with all rhetoric, we have to ask ourselves why we are being told something, and why in this particular way. What purpose does the speaker have? Does he want my money, my vote, my approval, my condemnation, my body, or my soul? The essence of modern critical thinking is to realize that for every observation, there is an observer.

Fictions carried too far are destructive. For instance, a hatred of the New York Yankees too easily morphs into starting fires and wrecking cars after a baseball game. It can even be the excuse for violence against Yankee fans.

You may well disagree with all the examples I've offered here. I'm not interested in gaining your agreement, just your awareness. Find your own examples. Be alert to all that passes around you. Expand your critical thinking into other spheres; I've named only a few. Many more fictions exist in advertising, films, religion, and—alas!—the classroom.

I don't suggest you become a moral prig, ruin the party, or fail to enjoy the agreeable emotions that are generated by some of the rhetoric that surrounds you. But remember that a fiction is not an absolute truth. The mind needs flexibility, not dead and entrapping metaphors.

Since I started with the ideas of one poet, I'll end with the words of another, Frederick Langbridge: "Two men look out through the same bars:/One sees the mud, and one the stars."

Use your intellect to help others out of their prisons. Help them see more than mud or, even, stars. To think critically is to be alive.

Francis Blessington is a professor in the Department of English.