Earth logic, she go boom.

I think I might possibly scream the next time I come across the following argument for the Patriot Act, the wars in Iraq and Afghanistan, Dubya's second term, or wiretapping:

"We are doing the right thing, because there hasn't been a terrorist attack on US soil since ______." [choose one]

• the Patriot Act was enacted
• we went into Iraq
• we went into Afghanistan
• eight months into Bush's first term
• we started listening to your pizza orders

Dude. This is so illogical that I want to vomit. But I will distract myself by waxing pedantic about this particular type of illogic. It is called the fallacy of post hoc ergo propter hoc, or "after this, therefore because of this."

Post hoc, as it likes to be called on the street, refers to a perceived relationship between two events. Event B happens after Event A, so therefore Event A must have caused Event B. You forget your umbrella one morning. Just before the end of the work day, you look outside. It's pouring. You berate yourself for forgetting your umbrella. Whenever you bring it, it doesn't rain; and when you don't, it does.

Post hoc has a sibling called cum hoc ergo propter hoc. Cum hoc, or "with this, therefore because of this," is known in statistical circles as a confusion of correlation and causation. Here, Event A and Event B occur at the same time, so either Event A must have caused Event B, or vice versa. Let's say you are taking a walk. Your cell phone rings. You stop to answer it. It's your dad, who is panicking because your mother has fallen and she can't get up. You happen to look down at your feet--and one of them is right on top of a crack in the sidewalk. As the guilt starts to set in, you start to hope that you still have your old therapist's number.

So obviously illogical, yet so disgustingly common.

So, okay. There hasn't been a terrorist attack on US soil since September 11, 2001. (I was in statistics class at that moment. It was my first semester of graduate school. We saw some stuff on TV during the break, but our professor didn't realize what exactly was going on, so we kept learning about standard deviations or whatever it was. Then right afterward we had our pictures taken for the student bulletin board. We all smiled, but those pictures turned out pretty creepy. But I digress). Guess what? Congress didn't pass the Patriot Act until late October. Guess what else? There wasn't a terrorist attack on US soil in those 6 weeks. There also wasn't one between September 11, 2001, and the initial invasions of Iraq or Afghanistan. Nor between September 11, 2001, and this creepy, unassailable wiretapping business. Nor in the first eight months of Bush's presidency. For that matter, there wasn't a foreign attack on US soil before September 11, 2001, in the first place.

Hm, if there hasn't been a terrorist attack on US soil since September 11, 2001, then there also hasn't been a terrorist attack on US soil since May 17, 2004. That's the day same-sex marriage became legal in Massachusetts. Therefore,

GAY MARRIAGE PREVENTS TERRORISM!

Eat your hearts out, ye defenders of homophobia, hegemony, and half-wittedness.