Appeal to an Unlikely Scenario

I mentioned in a previous post that I am currently taking an online course in critical thinking through Coursera. This week, one of our topics is fallacies of relevance. A fallacy of relevance is an argument in which the premises are of questionable relevance to the conclusion. An example is an appeal to an unlikely scenario.

Yesterday, the Senate Judiciary Committee held a hearing on Senator Dianne Feinstein's (D-CA) proposal to reinstate the ban on assault weapons and to ban high capacity magazines (clips holding more than ten rounds). Most of the media attention went to two celebrities who testified, former Representative Gabrielle Giffords and NRA president Wayne LaPierre. All three witnesses who argued against the bill maintained that assault weapons are needed by law-abiding citizens for self-defense in the event of an attack by armed criminals. However, as Senator Sheldon Whitehead (D-RI) pointed out, none of the anecdotes of successful self-defense involved an assault weapon or high-capacity magazine. They all utilized traditional weapons such as pistols or shotguns, access to which is not threatened by the legislation.

However, the pro-gun lobby's imagination is not constrained by reality, so one of the witnesses, Gayle Trotter of the Independent Women's Forum, entertained the Senators with the following hypothetical scenario:

An assault weapon in the hands of a young woman defending her babies in her home becomes a defense weapon. And the peace of mind that a woman has as she's facing three, four, five violent attackers, intruders in her home, with her children screaming in the background, the peace of mind that she has knowing that she has a scary-looking gun gives her more courage when she's fighting hardened, violent criminals. If we ban these weapons, you are putting women at a great disadvantage . . .

Appeals to unlikely scenarios should be evaluated by assessing the positive or negative consequences put forward in the scenario, weighted by their probability of occurrence—which in an unlikely scenario is low. They are compared to the positive or negative consequences of the alternative course of action, in this case, not banning assault weapons, weighted by their probability of occurrence. The conclusion is obvious.

Unfortunately for Ms. Trotter, she agreed to be interviewed on The Last Word with Lawrence O'Donnell last night. He effectively deconstructed her argument and made her look quite silly.

Another example of the mischief done by appeals to unlikely scenarios is the defense of torture which asks us to imagine that we have captured a terrorist who refuses to tell us the location of a bomb which will kill a large number of people. Given limited time, would we not torture him to find the bomb? One of the reason people find these unlikely scenarios to be plausible is that they are often presented in fictional films and television programs, and we later remember these stories as having been true.