One of the seemingly stranger logical terms a student may encounter when listening to a debate or reading a correspondence between two opposing partisans is red herring.
A quick check of the OED informs me that before it denoted an illogical relationship, red herring was part of a longer idiom derived from hunting. To draw a red herring across the track (or some similar verbal construction) meant that someone was using a smoked herring (which is a fish) to train hounds to follow a trail.
This earlier meaning does not contain any negative or fallacious connotations. However, as a logical term red herring is common fallacy that when employed will inhibit people from communicating about controversial topics without losing their cool.
Basically, a red herring is a big, bright, pink fish with a powerful odor. Although used initially to train hounds to follow a specific scent, the idiom associated with this process eventually came to mean something closer to its opposite.
To accuse a person making an argument of employing a red herring is to, in the broadest sense, accuse them of creating a diversion. Thus, instead of staying on course, instead of pursuing the topic at hand, by employing a red herring the speaker or the writer hopes to lead the audience away from the relevant trail.
After defining red herring, Robert J. Gula adds the following detail: "The red herring is invariably irrelevant and is often emotionally charged" (74).
It's the emotionally-charged aspect that makes this particular fallacy so insidious to group discussion. Once the topic of debate becomes obscure or unclear, the chances the discussion will be productive is nil. To illustrate the effectiveness, especially in group discussion, of the red herring let's look at the following extended dialogue.
Jack: "The problem that I have with him is the truck he bought. I mean, in this day and age, how can anyone justify purchasing a car or truck that doesn't at least get 30 miles per gallon. The environment is falling apart: the amount of arctic ice is shrinking which is causing the polar bears to die off, there are areas in the Gulf of Mexico the size of Massachusetts that cannot support any life--no fish, no plants, no amoebas, nothing. Dead zones they call them--now we got a new way to capture energy. An innovation called fracking which provides us with natural gas only at the expense of our ground water supply. I suppose no one is perfect, but I think that buying a car or truck is one decision in which a person should strongly consider the environmental impact of their purchase. It's not like there aren't beautiful and reliable cars and trucks that get 30 miles per gallon on the market.
Jill: "I think he would admit that there are beautiful and reliable cars and trucks that get 30 miles per gallon on the market, but he needs a truck for work that he can afford. The cost of a suitable work truck that gets 30 miles per gallon would cost him an extra fifteen thousand dollars."
Jack: "I guess some people are greedier than others. What's strange is that Mike is supposedly a Christian. Doesn't the Bible have a verse in it that prohibits greedy people from entering heaven?"
Jill: "That's not what the Bible says. Besides, the Bible verse I think your referring to may not have been intended literally."
Jack: "How do you know what the Bible writers intended? Maybe they intended every verse to be taken literally. I know when I write something very important, when I write something that I want people to understand clearly, I intend it to be taken literally."
Jill: "You've never written a metaphor or simile before? That's ridiculous. I know that you write song lyrics that have all sorts of figurative language in them."
Jack: "I haven't written song lyrics in like six months. But even if I have written song lyrics before that doesn't mean I use symbolic language all the time. I suppose you never use language literally? You're a lawyer for crying out loud."
Jill: "Exactly. In order to practice law, I needed to pass the bar. You think I took a stroll in Wrigleyville? Or that the judges brought in a Chubby Checker tape and the law students limboed our way into the profession?"
Jack: "Who's Chubby Checker?"
How does this dialogue look to you?
It seems all over the place, doesn't it?
It starts off focusing on the environment and whether an environmental concern, a vehicle's miles per gallon, should determine the vehicle a person purchases. This initial topic is abandoned when Jack uses a red herring in the second paragraph to respond to Jill's explanation. The composition of the Bible may be a fascinating topic to explore under the correct circumstances, but, in the above dialogue, Jack simply uses the Bible to divert the legitimate counter-claim that Jill makes.
Jack then introduces a second red herring into the discussion. Like biblical composition, biblical interpretation may be, under the proper circumstances, a fascinating topic to discuss, but in this dialogue, Jack simply uses it to complicate and divert Jill's focus.
Jill also uses a red herring. The issue that Jack brings up about his own employment of literal language is narrowly defined. Jill doesn't address the narrowness; rather, she broadens his meaning, and, in doing so, she complicates and diverts the direction of the dialogue.
This dialogue contains only two speakers, and it ends up sprawling into all kinds of complicated but unrelated topics. Also, I hope you get the sense of the emotional aspects creeping into each speaker's tone. Emotions are an important aspect of human judgment and human life, but appealing to emotion is not acceptable in logical reasoning. Anger, laughter, pity, sadness could each be appropriate mechanisms of persuasion, but they are not logical forms of persuasion.
The red herring can incite each one of these. And once an emotional incitement occurs, it is difficult to regain the civility and seriousness that was lost.
There are many nourishing items on the menu of logic. The red herring isn't one of them.