Illogical arguments can be persuavive.

If you're spoiling for a good argument, you may meet your match in Kathleen Farrell's office.

She is the chairperson of the department of communication at Saint Louis University. One of her academic interests is argument theory. In alternating years, she joins other argumentative intellectuals at argument conferences.

Aristotle introduced the formal study of argument, Farrell said. Millennia later, theories continue to evolve.

"Arguments are a special kind of communication. They make claims with reasoning, which assumes that someone is going to argue against what you have to say," Farrell said.

"The social scientific study of argument started in the World War I era. We had an Office of War Information for the very first time. It was trying to drum up support for the war," Farrell said. "People were starting to study in this fledgling field of psychology and communication, studying very systematically how people construct beliefs."

Argument theories have been revised in recent years to contend with evidence that an overwhelmingly illogical argument can be extremely persuasive.

"Argument has become more complicated contemporarily because now we know that people are persuaded not on the basis of long, developed, intricate lines of reasoning, but from fragments from here and there," Farrell said.

"There are so many sources of information. We don't have Stephen Douglas and Abraham Lincoln debating for three hours. We don't have long, developed lines of argument very often, except sometimes in court decisions. People are taking snatches of things from different kinds of sources and desperately trying to make sense of things.

"People have always been misled. It is now done in a more sophisticated way. That means we need to find new ways of trying to understand how argument works."

The sophistication of political argument has advanced considerably. Farrell said people continue to study the misleading "swiftboating" of 2004 presidential candidate John Kerry. By the end of that negative ad campaign, the decorated Vietnam War hero was viewed by many voters as a liar and coward.

"How in the world was that belief constructed?" Farrell asked. "Testimony is very powerful, and people believe there is something magical about people under fire, which means that every one of them tells the truth. If they can find three or four people who were under fire who said Kerry was a coward, we give great credence to that kind of evidence."

Ad hominem attacks on sources of inconvenient facts also are a powerful tool in modern argument. These are central to the arguments of fundamentalists and ideologues, Farrell said.

"Studying fundamentalist argument is very interesting--be it political, religious or scientific fundamentalism. Ideologues argue in particular kinds of ways. Ad hominem argument is a staple of ideological argument. They are attacking the person, not just in a trivial way but in a serious kind of way."

"Guilt by association," making one person responsible for the acts of a possibly remote other, is another staple of ideological argument.

"Be it 'birds of a feather flock together' or 'guilt by association,' people have a strong belief in that," Farrell said. "Guilt by association is an argument fallacy, but people who do argument theory say, 'Let's not argue about whether it is fight or wrong, the point is that it works. So let's try to figure out the source of belief in that line of reasoning.'"

Are there any among us who have not encountered a debate with a friend or associate (not to mention politicians or pundits) who seemed immune to recognized facts and logic? That is the nature of fundamentalist argument.

"Fundamentalists argue in absolutist terms. They have a full ideological construction of the world. They never argue from specifics up to general principals. They argue from the top down, from general principals to specifics," Farrell said.

On the journey from the top down, specifics are selected and deleted to protect the worldview. Discarding facts "is the very standard, typical argument of the ideologue. It is tremendously hard to argue with them unless you can demonstrate that their world construction is at fault."

The argument constructions of leftwing fundamentalists can be very similar to those of the fight wingers, whose constructions can be very similar to those of the Islamic religious fundamentalists they rhetorically attack, Farrell said.

"It is interesting to me how similar their arguments are at times. Consistent worldview, where everything ties together, is the landmark of ideological argument. People like consistent world views because they are comforting. So anything that feeds into that is very attractive."

Is the world going down the drain in a flush of spin and fallacy? Farrell likes to think it is not.

"I'm an optimist. I'm thinking maybe things will be a little bit better."

She pointed to the recent political controversy over proposals to fight high gasoline prices with a national gas tax holiday this summer. After presidential candidates John McCain and Hillary Clinton endorsed the idea, Barack Obama agreed with many economists that it was a pointless idea and a political ploy.

"Somehow, Joe C. Public in Indiana figured out that this gas tax holiday idea was pandering," Farrell said. "That means that the media did their job and that reasonable people recognized that."

Rick Stoff, a former St. Louis Globe Democrat reporter and editor, now practices public relations at his own firm, Stoff Communications