Should One Use a Bad Argument to Get a Good Result?

Here I noted that using Jovan Belcher's recent crimes as a soapbox to call for tighter gun control is a logically specious form of argumentation: a single, spectacular case does not significantly change the case for or against gun control at all; instead, the person using it is relying on the availability bias described by Daniel Kahneman. But this bias distorts policy in terrible ways. I recall once when a man was beheaded by an elevator that someone in the legislature immediately called for laws ensuring "this will never happen again." Of course, it had never happened before, and, as I recall Joe Bob Briggs noting at the time, legislation or no, it was never going to happen again anyway. A one in a trillion chance concatenation of events had taken place, and it was an utter waste of time and resources to devote any attention to it. But, the case sure was spectacular, and I bet the proposed "fix" got the lawmaker some TV facetime.

Frankly, I have paid little attention to the gun control debate, and so have no real opinion about who has the facts on the ground straight as to whether the risks of legally owned handguns outweigh the benefits. (And please don't use the comments section to educate me: that is not what this post is about!) What I do know is that the question can't be settled rationally by appealing to spectacular cases. Mr. Gun Control, if you can invoke Belcher, Mrs. Right To Carry can pull her "granny uses gun to fend off rapist" example to, and opinion will swing around based on who happens to have the best combination of recent and spectacular to pull from their sleeve. Emotional impact substitutes for analysis.

Now, an interesting question is, what if you are sure you are correct, but can only make progress with these appeals to emotion? Furthermore, you know the other side is going to use them when they can. Then, despite their logical irrelevance, is it justified to use these spectacular cases to your advantage? Mike in the comments section of the post I linked to above certainly thinks so: global warming is a serious threat, so it is fine to use the shock felt after Katrina to get people to "do something," despite the fact no one can say that Katrina was caused by global warming with any certainty.

I am wary of this approach. I can see that emotional appeal can be important in some cases: for instances, if I want to convince my kids not to drink and drive, I don't think using a spectacular crash of some celebrity they admire as a precautionary tale is a bad idea. But I am less sanguine about its use in policy, where there are usually two sides to a question -- unlike, say, drunk teenage driving, something for which I have heard few advocates! -- and these emotional appeals hinder our ability to think through the issue rationally.