Just in case you’ve been under a rock the last couple of years, there’s a lot of controversy surrounding Barry Bonds. He recently hit his 755th home run which ties him with Hank Aaron for the all time mark, and will soon hit 756. These last few weeks, listening to sports talk radio has been a virtual smorgasbord of bad reasoning. Since I’m about to start teaching a critical reasoning class in the fall, I thought I’d take a few minutes to highlight a few examples of bad reasoning that have been quite prevalent lately.

On ESPN Radio, I recently heard Amy Lawrence make an argument that went basically like this:

“Barry Bonds has never failed a steroids test. There is no proof that Bonds used steroids, so you can’t tell me that he did. In fact, if you say Bonds did use, then you’ve got to also say that everyone else used. We don’t have evidence that Alex Rodriguez didn’t use steroids so we can’t know that he didn’t.”

Now I don’t want to just sit here and bash on Lawrence because a lot of other people have made similar arguments, but this one is particularly bad because of the second argument about Rodriguez inserted at the end. Here’s why her argument is bad on a variety of levels.

1. Lawrence assumes that the only type of evidence is scientific evidence. If I think you’ve cheated in some way, then, according to Lawrence, the only way I can prove it is if there is a scientific test I can administer that’ll come back with certain results. The problem with this should be obvious. We make judgments all the time without scientific evidence. A couple gets divorced because one has good reason to think the other is cheating. No scientific evidence needed. A parent grounds the oldest child for tormenting the younger one. No scientific evidence needed. In both cases, all that is rationally needed is good reasons to think the spouse is cheating or the older child is being a brat.

   Now, are there other types of evidence available that gives us good reason to think Barry Bonds cheated? Of course. First, just look at the guy. The old eye test does wonders. Men over 35 don’t magically grow larger heads. He doesn’t just have a more muscular body, his head has actually gotten bigger (and you just thought it was his ego). That’s part of what human growth hormone (HGH) does to you. Secondly, there’s a book, The Game of Shadows, that details his usage with transcripts from informants, patterns of usage, dosages, etc. that clearly indicate he was using. Of course, the authors could’ve made it all up, but I haven’t heard one word from someone contradicting the evidence they provide. Finally, and the most damning in my opinion, is the fact that he admitted to using steroids under oath. Even if he didn’t know “the cream” and “the clear” were steroids (both of which he admitted to using), that doesn’t mean he didn’t use them. (“I’m sorry officer, I didn’t know this grass I was smoking is marijuana” usually doesn’t work.) The question shouldn’t be if he was using steroids, it should be if he knew he was using steroids.

   All this doesn’t just apply to Lawrence, these are all mistakes many people make when discussing the Barry Bonds and steroids issue. Next we’ll see a less common mistake (less common because it’s much worse).

2. Amy Lawrence suggests that if we say Bonds used steroids without “evidence,” then there’s no way to prevent someone from saying the same thing about Alex Rodriguez (A-Rod). This is a really bad argument because it boils down to nothing more than an argument from ignorance. The argument goes something like this:

   “We don’t know that A-Rod didn’t use steroids. Therefore, we can’t say that he didn’t.”

   In my critical reasoning class I teach the students that one way of refuting an argument is by logical analogy. Pretty much, you come up with a different argument that has the same structure that leads to an obviously wrong conclusion. So, let’s do that with Lawrence’s bad argument about A-Rod.

   “We don’t know that giant invisible martians don’t live on the moon and control everything we do. Therefore, we can’t say that giant invisible martians don’t live on the moon and control everything we do.”

   Same argument structure, crazy conclusion. So, we’ve seen that each part of her argument is flawed, but there’s another problem with the big picture.

3. In arguing about Bonds, Lawrence sets up a false dichotomy. A false dichotomy is an argument that tries to make a person choose 1 of 2 options when there is really more than those 2 options. Here’s how she committed this fallacy.

   Option 1: We don’t say Bonds used steroids.
   Option 2: We do say he used steroids & have to say the same thing about A-Rod.

   Lawrence leaves out the fact that we can say Bonds used steroids even though we don’t have a positive steroid test because we have other good reasons to say he did use them. The reasons we can say Bonds used steroids do not apply to A-Rod (doesn’t look abnormally large or have a growing head, but instead looks like a professional athlete would look given his workout regimen, there’s no detailed book giving other reasons to think he used, and he’s never admitted to unknowingly using in court).

So, thank you Amy Lawrence for providing me with many great examples of poor reasoning. After first hearing these really bad arguments I thought I’d just put in a CD whenever you fill in for someone, but now I think I’ll stay tuned in to see what other examples of poor reasoning you provide.