Appellate Advocacy Blog

Editor: Tessa L. Dysart
The University of Arizona
James E. Rogers College of Law

Tuesday, April 17, 2018

Thinking Thursdays--err, Tuesdays: Know your Logical Fallacies (Part 3)

Ruth Anne Robbins, Distinguished Clinical Professor of Law, Rutgers Law School

Sorry for the delay, folks. I fell victim to a distraction fallacy.

In my last two Thinking Thursdays, linked here and here, I discussed some common logical fallacies that lawyers may fall prey to. Specifically, I focused on non-sequitur fallacies, insufficient evidence fallacies, and shallow thinking fallacies. Today, I will talk about the last general category: avoidance fallacies.[1] The are also called fallacies of inference.

 When we make a valid argument, we employ a process of using true statements—such as a governing rule of law—to justify the truth of a new statement—i.e. the application of the law to presented facts. Logical fallacies happen when something goes wrong with the legal syllogism.

Logic1. An ad hominem attack challenges the ethos of one’s opponent (either the opposing party or that party’s counsel). Rather than meet the substance of the arguments made, the ad hominem attack claims that the person making the argument is a bad person or not worthy of trust for some reason. The person making ad hominem attacks end up making themself look petty and small, thereby losing some of their own valuable ethos. There are plentiful examples of ad hominem attacks happening on American politics, daily.

Note, however, that avoiding an ad hominem attack should not keep an attorney from attacking the credibility of a witness when the case warrants doing so.   

2. Someone using a straw man fallacy sets up a weak or absurd scenario attributed to the opposing side and then argues against it. This fallacy might take one of a few different forms. A slippery slope policy argument, taken to extremes can become a straw man fallacy. forms. For example, one might claim that since many heroin addicts began using marijuana before using heroin, marijuana use should be made illegal. Somebody opposing making marijuana use illegal might argue that most people began drinking milk before using heroin, so that milk should be outlawed too.

If you do this, however, you will ultimately lose credibility with the audience, because in the end your hypothetical or your imagined counterargument depends on being weak or ridiculous.

3. The last category has several names: red herring, distraction, deflection, misdirection. These are attempts to sidetrack the audience from the argument raised by another party, to hide a lack of a sound counterargument. Schematically it looks like this:

  • Speaker A: Milk chocolate is better-tasting than dark chocolate.  
  • Speaker B: Twenty percent of people surveyed last year believe that chocolate milk come from brown cows.
  • Speaker A: Seriously? 20%?

In law, it can go this way:

  • Major premise: The city may prohibit loudspeaker trucks from driving through residential neighborhoods from 8 pm to 8 am.
  • Minor premise: The city is attempting to enforce the code provision against a political candidate who has been using the trucks at 10 pm at night.
  • Conclusion (goes wide of the original premise’s mark): The city officials are trying to change the election’s outcome by enforcing the code against one party.

In an upcoming article, Professor Melissa Weresh talks in depth about the phenomenon of misdirection, and its place in legal argument.

For more reading about logical fallacies, the website Teachers Pay Teachers offer a variety of teaching materials at low cost that can help us understand what they are. Purdue’s Online Writing lab also offers a synopsis. And, there is also the amusing Illustrated Book of Bad Arguments that can help us learn.


[1] Thank you to Professor Ken Chestek (Wyoming) and Professor Steve Johansen (Lewis & Clark) for these examples. They come from the upcoming second edition of our co-authored textbook, Your Client’s Story: Persuasive Legal Writing (2d ed. Wolters Kluwer, expected publication date of later this year).

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