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Policy Debate

Logical Fallacies and Debate

by Glen Whitman

Introduction

This is a guide to using logical fallacies in debate. And when I say "using," I don't mean just pointing them out when opposing debaters commit them -- I mean deliberately committing them oneself, or finding ways to transform fallacious arguments into perfectly good ones.

Debate is, fortunately or not, an exercise in persuasion, wit, and rhetoric, not just logic. In a debate format that limits each debater's speaking time, it is simply not reasonable to expect every proposition or conclusion to follow precisely and rigorously from a clear set of premises stated at the outset. Instead, debaters have to bring together various facts, insights, and values that others share or can be persuaded to accept, and then show that those ideas lead more or less plausibly to a conclusion. Logic is a useful tool in this process, but it is not the only tool -- after all, "plausibility" is a fairly subjective matter that does not follow strict logical rules. Ultimately, the judge in a debate round has to decide which side's position is more plausible in light of the arguments given -- and the judge is required to pick one of those sides, even if logic alone dictates that "we do not know" is the answer to the question at hand.

Besides, let's be honest: debate is not just about finding truth, it's also about winning. If you think a fallacious argument can slide by and persuade the judge to vote for you, you're going to make it, right? The trick is not getting caught.

So why learn logical fallacies at all?

I can think of a couple of good reasons. First, it makes you look smart. If you can not only show that the opposition has made an error in reasoning, but you can give that error a name as well (in Latin!), it shows that you can think on your feet and that you understand the opposition's argument possibly better than they do.

Second, and maybe more importantly, pointing out a logical fallacy is a way of removing an argument from the debate rather than just weakening it. Much of the time, a debater will respond to an argument by simply stating a counterargument showing why the original argument is not terribly significant in comparison to other concerns, or shouldn't be taken seriously, or whatever. That kind of response is fine, except that the original argument still remains in the debate, albeit in a less persuasive form, and the opposition is free to mount a rhetorical offensive saying why it's important after all. On the other hand, if you can show that the original argument actually commits a logical fallacy, you put the opposition in the position of justifying why their original argument should be considered at all. If they can't come up with a darn good reason, then the argument is actually removed from the round.

Link to full essay:

http://www.csun.edu/~dgw61315/fallacies.html#Introduction

by Glen Whitman, former debater and Associate Professor of Economics at California State University at Northridge