Logic Lunch Counter

I also am a logic junkie. As a programmer and somebody who is good at math and analysis, I see these fallacies, like the "No True Scottsman" one, used all the time on the internet.

But I have something to tell you.

Most of the time you have no idea what you are doing. Please stop.

Let me explain.

Your first mistake is viewing the English language as some sort of system of formal logic. "If p then q" does not match very well, or at all, to the nuances, slipperiness, and complexities of modern languages. Spoken languages are not formal, complete, or deductive in nature. Many times we yearn for statements like "All men are mortal. Socrates is a man. Therefore Socrates is a mortal"

Or to quote from the site I linked (which was picked at random):

Inductive arguments needn't be as rigorous as deductive arguments in order to be good arguments. Good inductive arguments lend support to their conclusions, but even if their premises are true then that doesn't establish with 100% certainty that their conclusions are true. Even a good inductive argument with true premises might have a false conclusion; that the argument is a good one and that its premises are true only establishes that its conclusion is probably true. [I disagree about the use of the word "probably" here, as I point out in the rest of this piece]

All inductive arguments, even good ones, are therefore deductively invalid, and so "fallacious" in the strictest sense. The premises of an inductive argument do not, and are not intended to, entail the truth of the argument's conclusion, and so even the best inductive argument falls short of deductive validity.

So you really can't "prove" anything in a conversation the same way you can prove, say, that the the relationship between a hypotenuse and the two sides of a right triangle is a^2 = b^2 + c^2. Natural language discussions are inherently about persuasion, not proof. This means when you're reading a text you're weighing various rhetorical devices, including logical fallacies, to come up with a reasoned opinion. You are not conducting a proof.

Does this mean that logical fallacies are pointless? Far from it! What it means is that every form of communication is going to be chock-full of these fallacies. Natural conversation by good, intelligent, open-minded, reasonable, and polite people has all kinds of logical fallacies peppered throughout.

I was reading an article the other day espousing an opinion I support. In it, the author made resonable claims and advanced a thesis by use of example, deduction, induction, and observation in a spirit of what seemed to be even-handedness. In the middle of it, however, he said something which basically boiled down to "and the people that support my opponents are idiots"

Almost immediately the logic mavens popped out of the woodwork, pointing out that this was an egregious Ad Hominem attack on his opponent.

That's all fine and dandy, except it wasn't. It was an attempt to impeach supporters of his opponent. It might have been an attempt to assassinate the character of his opponent by association (which is a subtle form of Ad Hominem), but it was definitely not a direct attack on the ability of his opponent to speak.

Steve Forbes posted a piece on net neutrality a while back. Steve propped up Google and Congress as his opponents, and then proceeded to explain why they were all corrupt, out to make as much money as they can, and stifle innovation.

Almost immediately folks started crying "Straw Man! Forbes is making a Straw Man argument!"

That's all fine and dandy except for this: when you're writing an essay and want to include the views of people you disagree with, you have to make some sort of assumptions that don't work about the motivations of your opponents. I remember reading Paul Graham talk about OOP programmers as something like "they're the type of people who like wiring little pieces together. That's fine if you're that type of person". I immediately thought damn Paul! Straw Man much? But he was honestly just trying to point out the views of people that had different opinions than him.That's how essays work. Good authors quote their opponents, at length, or say they don't know for sure. Bad ones make sweeping statements (as Forbes did in this piece, which I found atrocious for a man of Forbes' background) or dress up their opponents in garb that even their mothers would find offensive.

That's the way these things work: persuasion is full of varying degrees of fallacies strung together. Good persuaders lull you into a kind of trance where they can slide by all sorts of zingers. Bad ones just punch you in the nose with them. If you agree with me I can sneak in more zingers without your noticing. If you don't agree with me (and are logically inclined) you're going to spot each and every slip no matter how minor or related to the larger argument I'm making. All articles are guilty of bad reasoning -- that's the way it's supposed to work!

The way I use these lists of fallacious argument types is really as more of a commentary on the style of a piece, not the quality of the overall public discussion one way or another. If I say "That's obviously just an Ad Hominem attack" what I mean is "This author is so bad that they're just pulling out easy rhetorical tricks instead of actually doing any work to make a case" And I've read some awful tripe on the net. I've read 500-word articles that were just long streams of how stupid, bad, corrupt, ugly, dumb, fat, etc the other people are and aren't we so glad we're not them.

So for all you guys who have taken a logic or debating course or found the websites and essays that tell you about logical fallacies? Congratulations! You're beginning to learn how to think critically. Now get over the pointless and self-serving labeling already and move to the next step where we can all engage material critically from multiple points of view to see if there's anything of value in there for all of us.