Logical fallacies are everywhere. Just make a search online using the string ‘logical fallacies list’ (e.g., here, here, and here), and you’ll come across many lists citing many more fallacies that an arguer can employ, and why they are wrong, bad, or otherwise socially unacceptable. The authors of such lists argue that it is desirable, when crafting a valid argument, to avoid as many of these fallacies as possible and, when consuming an argument, to be sensitive to their presence.
And yet the number of fallacies in day-to-day discourse never seems to diminish. So, clearly, people aren’t getting the message.
Of course, not everyone making an argument is really interested in making their argument valid. Certainly, politicians are interested more in getting votes or passing their particular bills into law than they are ever interested in logic and logical fallacies. Advertisers also bend the rules of good logic to make their product stand out so that potential customers will select their product over a competitor’s. So people who fall into these classes reject the message because embracing it would compromise their goals.
But there is another facet worth considering as well. There is a possibility that people do get the message and simply reject it since they judge that the message itself is flawed. Is it possible that some people’s common sense allows them, perhaps unconsciously, to see that some arguments about fallacies are themselves fallacious? Is it possible that some people who argue about avoiding fallacies are engaging in fallacies about fallacies?
Now, before I explain how some arguments about fallacies can be fallacious, I would like to clarify a couple of points. First, I think the best definition of a fallacy is provided by the Stanford Encyclopedia of Philosophy, which says that a fallacy is a deceptively bad argument; an argument where the conclusion that does not follow from the premises being offered and that it is not manifestly obvious why. Second, that that definition, while being the best out there, is still fairly inadequate. The reason is that, if one can detect the fallacy, how deceptive is it actually? The point here is that the very concept of a fallacy is a slippery one and, in fact, there is substantial controversy about the nature of fallacies as can be seen from the long discussion here.
So, for the sake of this post, I am going to argue that a fallacy is a bad argument that is deceptive for people who are not trained in detecting and correcting it.
Some fallacies are relatively easy to detect and fix. The simplest ones seem to originate in deductive reasoning. The following example of the fallacy of the undistributed middle comes from syllogistic logic:
My cat has fur
Therefore my cat is a dog
These types of errors are easy to see even if they are not easy to explain. These types of fallacies are benign because they aren’t very deceptive.
A much more common and truly deceptive fallacy comes in the form of equivocation, where the meaning of a term changes mid-argument and, if one isn’t careful, one misses it and becomes either confused or, worse, convinced of an invalid conclusion.
When the argument is simple, equivocation is fairly easy to find, as in this example:
Happiness is the end of life.
So, death is happiness.
Clearly the word ‘end’ in the first line means the termination or cessation whereas the word ‘end’ in the second means goal or purpose. When the argument is much larger in length or involves an emotional subject it is much harder to detect equivocation. As an example on that front, I once read a blog post (unfortunately I can’t source it anymore) where the author was celebrating a story in which an Amish man boarded a bus and challenged the people onboard about television. As the story goes, the Amish man asked how many of the passengers had a TV and every hand went up. He then asked them how many of them thought TV was bad and almost every hand went up as well. He then asked why, if they thought it was bad, did they tolerate a TV in their homes. The blogger obviously didn’t notice or care that the definition of TV had changed from the first question, where it meant the device, to the second question, where it meant the programming. All that mattered was the emotional delivery.
Perhaps the trickiest kind of fallacy concerns appeals to authority. And it is in this case where we find fertile ground where grow the fallacy of fallacies.
An appeal to authority can actually be a reasonable thing to do when dealing with custom, or policy, or doctrine. As long as the authority is proper, the appeal can be a solid piece in an argument. When the appeal is to the authority of the public or to someone whose motives are questionable, then the appeal to authority becomes a fallacy.
That said, an appeal to authority is never valid when it comes to science. Nonetheless, it is a common place appeal offered by those who talk about ‘settled science’. They tell us that a scientific conclusion is valid based solely on the idea that ‘X percent of the scientists in the world agree on proposition Y’. They also tell us that anyone who objects is necessarily engaged in a logical fallacy by either ignoring a proper appeal to authority (the X percent of scientists who believe proposition Y) or by making an incorrect appeal to authority (the 100 – X percent of scientists who reject proposition Y).
To my way of thinking, as a physicist, this type of argument goes against common sense and is just wrong. Consider the case in physics at the turn on the 20th century. A majority of scientists felt that mankind had basically all the rules in place. The science of mechanics was well understood in terms of Newton and his 3 laws and the science of electricity, magnetism, and optics had just been united by Maxwell. Sure there was this pesky little problem with the ultra-violet catastrophe, but the majority of scientists were willing to ignore this or believe that a small tweak was all that was needed to fix things. Of course, that ‘small tweak’ ushered in the science of quantum mechanics that forever changed the way we think about science and philosophy.
Now a careful reader may argue that I indulged in a logical fallacy of my own about the majority of scientists when I pronounced that they were willing to ignore or believe all that was needed was a small tweak. After all, was I there to interview each and every one of them? But that assessment is backed up by an overwhelming amount of evidence that shows that the advancement of Planck was surprise to the physics community.
So what to make of those ‘settled science’ folk? Well they seem to want to ignore the logic underpinning the scientific method by appealing to authority as if scientific conclusions are immutable as long as they are based on a kind of popularity. They also use the form and structure developed to explain logical fallacies as an additional appeal to authority (in this case to the community of logicians rather than scientists) to dismiss anyone who believes the contrary to their doctrine as being illogical. And here they commit a two-fold error. By failing to recognize that there is no certainty encompassing either science or logic in their entirety, these individuals use the machinery of avoiding fallacies as a logical fallacy itself. They look on those who support the doctrine as pure in motive and look upon those who reject it as either corrupt or unqualified and stupid. They heap on layer after layer of emotionalism while telling their critics that they are mired in emotional thinking.
Fortunately, it seems, the human mind has a built-in safety valve in the form of common sense that allows us to reject these fallacies of fallacies even if we don’t know why we do it. I suppose, intrinsic to the human condition, is a natural skepticism for just how far logic can takes us. After all, it is a tool not a god and we should treat it as such.