3. Using Logic in Argument

Logic can be a complicated concept, but the bottom line is simple: statements in your argument need to be valid and they need to make sense. Logical fallacies – or errors in reasoning – can weaken an argument and strengthen your opponent’s argument against you. Sometimes they can be hard to find, but with a little thought put into revising your paper, you can identify possible logical fallacies.

Although we could spend a semester discussing logic and logical fallacies, I’ve listed a few below and will also give you a practice in this module’s multi-part exercise.

  • Hasty generalizations: Basing an argument on insufficient or unsupported evidence. Let’s say you go to McDonald’s on Cornelia Street, and they serve you cold french fries. If you start telling everyone McDonald’s serves cold french fries, you’ve used a hasty generalization. People often do that when telling others about products or services they received. If you go to a thousand McDonald’s and all of them served cold french fries (ugh), then you’d have something to argue about.
  • Non sequitur (it doesn’t follow): Stating a conclusion that is not necessarily a logical result of the facts. If you see in the catalog of courses for the upcoming semester that Mel Gibson is teaching a course in acting, you might automatically think that would be a great course to take because of the teacher. Just because Gibson is an actor does not necessarily mean he will be a good teacher. Great baseball players don’t always make good coaches. You need proof of Mel’s teaching ability before you can say he’s a good teacher.
  • Begging the question: Presenting as truth what is supposed to be proven by the argument. Stating that your argument for a ban on violent video games is needed because video games cause violence is begging the question. It’s not a proven fact until you show sufficient evidence to support that. Often, your facts need to be proven in argument.
  • Ad hominem (to the man): Attacking an opponent’s character rather than the opponent’s argument. Criticizing a political candidate because he or she is divorced or had a drinking problem in the past is not good logic. What is the candidate’s record in serving the people? How is the candidate as a public servant? What is his/her platform? His/her personal life doesn’t make for good argument (though we all try: look at President Trump, for example).
  • Distraction: Drawing the reader’s attention away from the issue with unrelated information. You argue that there are too many commercials in today’s television programming. You point out that televisions today are crystal clear: the reception is so nice that you almost seem to be seeing things live. That has nothing to do with the argument but brightens the reader’s perception of the general topic. It’s not good support.
  • False analogy: Making a general statement based on a weak comparison. Look closely at your use of metaphors (comparisons). Make sure the two items are similar. People should ignore the smoking ban in restaurants and bars because they ignore the ban on using cell phones while driving. Two separate issues that are enforced differently. It weakens an argument.
  • Either/or fallacy: Trying to convince your reader that there are only two sides to an issue, one right, one wrong. Seldom are arguments this clear. If they were, there would be no argument. The whole issue used recently that people in America who didn’t support the war on Iraq were un-American is a prime example of either or. Many forgot the issue that Americans have a right to voice their opinion. Logic was thrown out the window, mainly because of emotional impact.
  • False premise: Making an assumption that is not true. Everyone likes science fiction movies, so everyone should go see “Star Wars.” Lots of people, obviously don’t like science fiction. A better argument would be to look at how “Star Wars” has qualities that will attract both science fiction fans and people who don’t like science fiction.
  • Name calling and genetic fallacy: Using terminology to invoke an emotional response. I once had a student write about gun control (she opposed it). In her very first paragraph, she used the term “bleeding-heart liberals.” Right away, she’s strengthened her argument with those who support her but has lost all who oppose her and created a sense of doubt in the main audience, those undecided. Don’t call people names. The old argument that Billy is bad because his dad spent time in prison is the prime example of genetic fallacy.
  • Appeal to ignorance: Arguing that one thing is true because its opposite has not been proven true. The old argument at election time: voting for one candidate because the other candidate has nothing of value. That is such a weak statement of our political system. We need to have reasons for voting for a candidate, not for voting against another candidate.

Again, this is a brief look at a very complex idea. Study logical fallacies (look it up in your search engines). But most importantly, think about what your opponent’s reaction is going to be to every statement of fact you make in argument. Don’t give your opponent ammunition for his/her argument.