Welcome to Logical Fallacies 101, an ongoing exercise to help foster more reasonable debate on Newsvine and wherever else you may find yourself discussing differences of opinion.
I've gotten a lot of very kind and appreciative feedback on this series, from people learning about fallacies for the first time, those needing a refresher course, and people who just want something to point to during a debate. This is the fifth edition of Logical Fallacies 101, after ad hominem, association, argument from ignorance, and begging the question.
These are meant to be quick, easily-digestible logic primers. The basic definition of a fallacy established earlier in the series is...
A fallacy is a rhetorical sequence that doesn't logically connect. For a variety of reasons, logical fallacies are invalid. A logical fallacy does not necessarily render the point invalid, but it means you need to rethink how you're making your point.
Today we're going to take a break from misused words, and instead steer towards a fallacy that's disturbingly popular...
When I say "argumentum ad populum" is a popular fallacy, I'm not just making a cheeky joke -- though admittedly, I'm doing that too. The fact is that next to the ad hominem, this is one of the most frequently used abused fallacies spouted in amateur debate. It even has a variety of names: appeal to the majority, appeal to the people, and the bandwagon fallacy. If you know what a bandwagon is, you can probably see where this one is going.
The "argument by consensus" claims that a widely-held belief is true, and that truth is clear because it is a widely-held belief. It's circular reasoning at its finest, folks, and doesn't stand up to scrutiny. If 99% of the population thinks the world is flat, their consensus doesn't make the supposition true. It makes 99% of people kind of dumb.
We see this kind of reasoning used in advertising a lot, and why not? Their point is to sell products, not make fallacy-free arguments. In the realm of politics, however, we see it all the time. It lends extra credence to someone on the basis of popularity, rather than accuracy. You might hear a conservative say:
Glenn Beck gets huge ratings, he must be doing something right!
I'm not trying to pick on Glenn Beck -- okay, maybe a little -- but his impressive market share doesn't really mean anything about the veracity of his statements. If he says something that's demonstrably incorrect, it remains incorrect no matter how many viewers watched it and believed it. Of course, conservatives aren't alone:
Most of the world is happier with Obama in office than they were with Bush, so his foreign policy is better.
Even assuming the assertion is true, which is pretty hazy at best, foreign policy isn't judged entirely by how much we're liked on the world stage. Arguing in favor (or against) specific foreign policy decisions is fine, arguing that he's right (or wrong) due to popularity (or unpopularity) is not.
Of course, this inevitably brings up a related issue in politics: polls. Let's be very clear about what polls are and what they aren't. Polls provide insight into what people believe, no what is logically correct. For that reason, you should be careful about the conclusions you draw when citing polls. To take a recent, hot-bed example:
Roughly two-thirds of Americans believe Wisconsin unions should keep collective bargaining rights.
Now, this is a fact, shown by a variety of polls. However, using it as your entire argument in favor of the collective bargaining rights is fallacious. Unless you believe that our elected representatives are avatars for the wishes of their constituents (populist governance), and can carry that philosophy through all of your political views, you need to argue some reason why the collective bargaining rights are important.
Let's look at a similar example from the other side.
Most Americans oppose gay marriage.
True, but when embroiled in a discussion of whether or not marriage is a civil right that should be given to homosexuals, it really doesn't matter what "most Americans" think. The opinion of the majority doesn't override the rights of the minority.
Note: You could, alternatively, argue that the polled consensus means that actions would be the smart thing to do, politically. Politicians who do popular things tend to get reelected. So you could argue, for example, that a politician is "playing it safe" by keeping Wisconsin collective bargaining or opposing gay marriage, which is justifiable from a certain perspective.
Great minds think for themselves. The argument by consensus follows the herd -- when convenient to do so.