Recent history has fostered a profound distrust of persuasive rhetoric, but we’d be wiser to heed the power of words.

P.T. Barnum made a fortune from freak shows. Barnum’s so-called freaks were performers or in some cases, like the “Fejee Mermaid,” inanimate objects – defined less by their own bodies than by the acts Barnum concocted for them. The "Brick Man," for instance, was an unremarkable-looking person who drew crowds simply by wandering around outside the American Museum and, per Barnum's instructions, moving bricks from one spot to another in a seemingly obsessive manner. (Shazam.)

When Barnum advertised his freak shows, he deliberately nurtured the public’s suspicion that his "freaks" might be fakes; he called himself the Prince of Humbug. Although Barnum didn't promise his freaks were real, he did promise to give his audiences the "full equivalent" of the price of admission. What people received in exchange for their money was an opportunity to test their wits – to decide for themselves whether they were being had. Barnum understood that there is pleasure in skepticism. It’s heady to feel that you're nobody's fool.

So let us give thanks, ladies and gentlemen, boys and girls, for the many opportunities for doubt and wariness we have enjoyed over the past six months as the rhetoric of the economic meltdown has swirled around us. Bankers and auto makers have pled their cases with a studied mix of sheepishness and gravity. Politicians, union leaders, and lapsed regulators have all said their bit. If P.T. Barnum gave his audiences a taste of humbug to savour, our current climate offers us a feast we can hardly take in.

But doubt, like any pleasure, can be indulged to excess. It can make us sick. Even before the economic crisis raised public skepticism in North America to its current pitch, distrust of our leaders was strong. A few years ago, Environics found nearly half (48 per cent) of all Canadians agreeing, "It doesn't matter what our political, economic or business leaders propose, I absolutely do not believe them."

This kind of indiscriminate disbelief is evident in our collective dismissal of rhetoric. We tend to speak of rhetoric scornfully, as though deception is inherent in all persuasion. Barack Obama's sonorous campaign speeches roused millions – and so attracted suspicion. A few headlines from the U.S. campaign trail: "Obama's rhetoric soars, but what does his record suggest?" "The hollowness behind Obama's rhetoric." "Indian government dismisses Obama 'rhetoric' on Kashmir." Rhetoric has a reputation as a front for inaction and a breeding ground for lies. Watch it: that guy's a smooth talker.

Aristotle wrote his seminal text on rhetoric partly as a rebuke to assumptions like these. He saw rhetoric being dismissed as an essentially fishy art, when in fact it could do noble work. "And if it be objected," he wrote, "that one who uses such power of speech unjustly may do great harm, that is a charge which may be made in common against all good things except virtue, and above all against the things that are most useful, as strength, health, wealth, generalship. A man can confer the greatest of benefits by a right use of these, and inflict the greatest injuries by using them wrongly." For Aristotle, the fact that rhetoric could cut both ways was precisely why it deserved careful attention.

Like a bank balance sheet, our rhetorical environment contains plenty of hidden toxicity. But dismissing the whole thing – tempting when we feel betrayed – is little better than swallowing the lies. When it comes to making sound decisions, unwavering skepticism is as useless as unwavering credulity, and probably more corrosive to the soul.

We are wrong to disown rhetoric. We have plenty of media-studies courses, and the dread cliché, “healthy dialogue,” is everywhere. But how well do we understand what happens inside us – both rationally and emotionally – when a human being looks us in the eye and tries to convince us of something? We are obsessed with “credibility” lost and found, but how keenly do we perceive what Aristotle called the ethical appeal: the persuasive power that flows from the personal virtue of an orator?

Calling every CEO, politician, banker, union leader, and economist a huckster is easy, and, as P.T. Barnum knew, there is pleasure in the judging. But listening closely to each other – attending to the logic and spirit of what is asked of us – is the more worthy project. Moreover, Aristotle argued that rhetoric is not the art of persuasion, but the art of discerning the available means of persuasion. Listening well is as vital to the economy of ideas as speaking well. If we do a good job of sifting through the competing claims on our trust, we will ultimately make our own ideas more worthy of others' hearing. Maybe that's the best way home from the circus.