Bad logic makes bad humor.

While I appreciate Alanna's brand of fun and humor, and enjoy her comments on my blog, I simply cannot allow the awful joke she related in the comments to this post to go unchallenged. I've always hated that joke. I don't hate it because it's a bad joke, I hate it because it's bad logic. (I also think it's a bad joke because it doesn't make sense, because it's bad logic.) Here's the "joke": Descartes is sitting at a bar. The bartender asks him if he wants another drink. He says, "I think not." Then he disappears. The background is the famous cogito: Descartes proved to himself that he existed by reasoning, I think, therefore I am. Presumably, the alleged joke is trying to do a kind of reverse modus tollens, resulting in this argument:

1. If I think, then I am.
2. I think not. Therefore,
3. I do not exist.

The problem with this argument is that it's not valid. We can't go from if A then B and not A to not B. We can go from if A then B and A to B (modus ponens), or from if A then B and not B to not A (modus tollens), but the step the "joke" relies on just doesn't work. To illustrate, there are lots of examples of things that do not think but nevertheless exist. My spiced pumpkin candle, for instance. The following are recastings of the joke which are based on good logic. I recommend that if you ever feel the need to tell a Descartes-at-a-bar joke, you tell one of these: MP: Descartes is sitting at a bar, and the bartender asks him if he'll have another drink. "Yes, I think I will," says Descartes. Suddenly, he continues to exist. MT: Descartes is sitting at a bar, and the bartender asks him if he'll have another drink. Descartes suddenly disappears. "Well, I guess I'll take that as an 'I think not'," says the bartender. AC: Descartes is sitting at a bar, and the bartender asks him if he wants another drink. "Well, I do but I don't," says Descartes. Suddenly, everything happens. W: Descartes is sitting at a bar, and the bartender asks him if needs another drink, and tells the assistant bartender that she must, if Descartes says yes, get him one. Suddenly, Descartes becomes very, very thirsty.

Guns! On campus!

There's some controversy here at Brown this week because of the new decision to arm our campus police officers. Apparently, there was a safety audit in 2001 which recommended a bunch of stuff, including the arming of the police force, and Brown higher-ups have spent the better part of three years deciding whether to follow the recommendation. And now, some people are relieved, and some people think the decision was wrong. I have a hard time seeing what all the fuss is about. Some people just seem to be genuinely scared. I find this baffling. I'm as paranoid about police as the next guy, but I'm not afraid of them abusing their guns. I've heard people who seem genuinely to expect that if the Brown police are armed, then they will go trigger-happy and end up slaughtering students. I was an undergraduate at Rice, which is much smaller than Brown, and much more closed off from the rest of the world. Rice is surrounded by a three-mile perimeter of hedges. Rice campus police are armed. For all I know they always have been (anyone know?). I never found it odd. I occasionally had my problems with the way the Rice police acted -- I do have a couple incidents in mind in which I considered their actions to have overstepped reasonable bounds. But the idea of one of them misusing a firearm never would have occurred to me. Brown, by contrast, is in the middle of everywhere and open to everything (Half the time when I'm walking in the area, I don't know whether I'm on campus or not.) Brown apparently lies near some pretty shady neighborhoods. Every week, I read reports about students getting mugged and beaten. Apparently, official policy for the unarmed police at Brown was to walk away from any violence and phone Providence police, who eventually show up. I absolutely cannot understand why so many people think this is a scary idea. I don't understand why it took three years to decide -- it really feels like a no-brainer. What's the point of a police force that can't engage crime?

yuck yuck.

Joshua's latest post at Blogosophy reminded me of a philosophy joke I made up a couple years ago. I'm reasonably certain that I developed it independantly, but I also find it very, very likely that I wasn't the first person to do so. Why should you never insult Descartes' honor? Answer in comments.

There's still football

An AOL Sports headline right now is "An All-Missouri Super Bowl?" I'm embarassed to report several seconds of confusion, until I realized that the St. Louis Rams and the Kansas City Chiefs are each located in the state of Missouri. While I would have answered correctly if asked, "in what state is St. Louis/Kansas City where the Chiefs play?", I don't think I've ever realized that Missouri had even one NFL team. Speaking of NFL teams, the 49ers are officially out of the playoff race. Yeah, it hurts, but it's time for me to move on as a football fan. It could go without saying that I will still root for the 49ers in their remaining games, but now that I'm not thinking about playoffs, my opinions towards many of the other games change. (When your team is on the wildcard bubble, there are a lot of teams you have to root against.) So, my revised preferences, which reflect right now. Don't expect them to be the same next week, and certainly don't expect them to be the same next year: Teams I generally have positive feelings toward:

• San Francisco 49ers
• Detroit Lions
• New England Patriots
• Houston Texans
• Cincinnati Bengals
• The entire AFC South

Self-reflection observation: I expected that since the 49ers were out of the playoff picture, I'd find myself feeling positive about a few more NFC teams now. But I really can't bring myself to root for any of the NFC contenders at this point. I guess I like the Panthers. I'm neutral toward the Cowboys, which is better than most of the NFC. Teams I generally have negative feelings toward:

• Baltimore Ravens
• Green Bay Packers
• Philadelphia Eagles
• New York Giants
• Kansas City Chiefs

Teams I hate with a white-hot passion whose inner fires are slowly but surely broiling the soul within me:

• St. Louis Rams

If I have to choose actual condenters, I'll take the Patriots to win the AFC. The NFC playoff race will be a matchups game -- which team do I hate more? I just want to see the Rams go down hard, again. (In shootouts, where Marc Bulger nevertheless continues to put up good numbers for my fantasy team.)

To bandwagon or not to bandwagon...

Brayden King provides this link: www.firedenniserickson.com. For the record, I don't have strong feelings about the guy, although I definitely miss Mooch.

It's been a while since I've thought about epistemology...

Suppose I'm omniscient. This means that I know every true proposition, and also have no false beliefs. Therefore, I must know I'm omniscient, since I'm omniscient is a true proposition. If I know X, then I have X's content as a justified true belief. Therefore, I must be justified in believing that I'm omniscient. What could justify a belief like this? We might be tempted to say that it's justified in virtue of the fact that I'm omniscient. If I knew I was omniscient and discovered a belief in myself, I'd be justified in believing it to be true. But I can't assume my omniscience in justifying that belief -- that's a tight circle. We could do it if we were externalists about justification pretty easily... taking my beliefs as true would be a reliable mechanism. But it'd be kind of surprising if the possibility of an omniscient being implied externalism about justification.

Good morrow good Monday...

I hope that everyone had a nice Thanksgiving. I got a fairly substantial amount of work done, and did a lot of sitting around, but apparently not a lot of blogging. I think I'm considering myself back now, and you may reasonably expect to see me more active here. I've been thinking about omniscience this afternoon; there may be a post in the near future. I'm also thinking about the NFL -- with the 49ers sadly out of the playoff picture at this point, my perspective changes dramatically. But first, I want to go home, and prepare some food, and eat it.