LSAT lessons from rappers

Geto Boys LSAT homework solution

Wow, do I love my students. Yesterday, I had the Geto Boys teach an LSAT lesson. The lesson ended with a tongue-in-cheek "homework assignment" that I figured nobody would actually respond to. But PJ Lin, one of my online students, submitted a response. PJ received his class binder in Atlanta, GA and is now "traveling." Since PJ views his LSAT lessons from somewhere in the world, let's just say that he's from "parts unknown"... like the Ultimate Warrior.

(Source: wwe.com)

I'm sure PJ's response is correct, because he's already an LSAT All-Star at the very least, and might very well be on his way to an Intercontinental Championship. (The Ultimate Warrior first got the Belt by defeating the Honky Tonk Man in 27 seconds, according to Wikipedia.) In this post, I'll comment on PJ's response. Call me "Mean Gene."

(Source: awesomehq.com)

Here was the prompt:

And real gangsta-ass niggas don't run for shit  'cause real gangsta-ass niggas can't run fast  

What's the evidence? What's the conclusion? What's the missing piece? How would you answer a Sufficient Assumption question based on this argument? A Necessary Assumption question? A Weaken question?

According to PJ,

conclusion is gangsta don't run for shit

premise is gangsta cannot run fast

Correct! PJ then provides the missing piece:

the missing piece is p2

 p1 if you are a real gangsta you cannot run fast (G--> ~RF)

p2 not running fast makes you not run for shit (~RF--> ~RFS)

C: if you are a real gangsta you don't run for shit (G--> ~RFS)

Correct again! Then PJ proceeds through the different types of questions that the testmakers might ask based on this argument. If the testmakers had asked "Which one of the following, if assumed, would allow the conclusion to be properly drawn"...

sufficient assumption answer is:

if you do not run fast then you do not run for shit

Yep. If the above statement is true, then the Geto Boys argument wins. That's the definition of "Sufficient Assumption."

So, what if the testmakers had asked "Which of the following is an assumption on which the argument depends?"

assumption required:

there is at least one person who cannot run fast that does not run for shit

Yep. If the above statement is false, the Geto Boys' argument would lose. That's the definition of "Necessary Assumption."

So, what if the testmakers had asked "Which of the following, if true, would most undermine the conclusion of the argument?"

weaken:

everyone who cannot run fast always runs for shit.

Yep, if that's true then the Geto Boys' argument definitely loses.

What's everybody think? Does PJ immediately win the Intercontinental Championship Belt? I think he deserves it.

 

An LSAT lesson from the Geto Boys

A couple weeks ago, we looked at Dr. Dre's three necessities. (Be sure to invite him to your party after stocking up on Chronic, Remy Martin, and soda pop.) Today we're going to identify some assumptions in the Geto Boys' 1992 "Damn It Feels Good to Be a Gangsta." (Have a listen?)

(Source:  15 Things you Didn't know about Office Space on blog.koldcast.tv)

The Geto Boys don't waste any time getting into their LSAT lesson.  The first verse includes this:

And niggas always gotta high cap Showin' all his boys how he shot em But real gangsta-ass niggas don't flex nuts  'cause real gangsta-ass niggas know they got em 

(Source:  lyricsfreak.com)

Focus on the last two lines:  "real gangsta-ass niggas don't flex nuts, 'cause real gangsta-ass niggas know they got em."

I think that makes sense. Do you? (If not, take a quick visit to Urban Dictionary for a definition of "flex nuts.")  OK... everybody on board? The argument makes sense to me, because when you know you got 'em, why would you need to flex? It's not important what other people know, right? It's important what you know. Quick poker analogy: In poker, "the nuts" means the best possible hand. If you're holding the best possible hand, you'd want to do everything you could to hide that fact from your fellow players... so you could take all their money.

So anyway, the argument makes sense. But in LSAT terms, it's actually incomplete. It's not wrong, but it's missing something. The Boys have offered one premise and one conclusion. And there's a bit of a disconnect between those two. Can you find the evidence? Can you find the conclusion?

The word "'cause" is the clue here. When you say "X, because Y," you're saying that Y is the reason for X. So when the Geto Boys say "real gangsta-ass niggas don't flex nuts," they're starting with their conclusion. Next, they offer the evidence for that conclusion: "'cause real gangsta-ass niggas know they got em."

I don't usually diagram LSAT Logical Reasoning questions unless I absolutely have to, but I sometimes do it for teaching purposes. Here's my starting diagram:

Something's missing! The premise "if you're gangsta, you know you got 'em" talks about knowledge, while the conclusion "gangstas don't flex" talks about action. The Boys have assumed that if you know you've got the nuts, you won't flex.  Like this:

Based on the argument above (before I added the missing piece) LSAC could write a variety of different LSAT questions.

If the testmakers wanted you to identify the missing premise that would prove the truth of the conclusion, they could make it a Sufficient Assumption question:

Which one of the following, if true, would allow the conclusion to be properly drawn?

Answer:  Nobody who has nuts would ever flex them. If that's true, then the argument wins. So that would be a perfect answer for a Sufficient Assumption question.

Or the testmakers could ask you identify a missing piece that, if untrue, would cause the argument to fail. That would be a Necessary Assumption question, like this:

Which one of the following is an assumption required by the argument?

Answer:  At least one person who has nuts doesn't flex them. (This is necessary, because if it's untrue it becomes "everybody with nuts does flex them," which would invalidate the Geto Boys' argument.)

The testmakers could also phrase a Necessary Assumption question as a Must Be True. What if they said this?

If all of the above statements are true, which one of the following must also be true?

Same answer as immediately above: At least one person who has nuts doesn't flex them. That fact must be true, if the Geto Boys' argument is true.

The testmakers could also ask you to attack the argument... a Weaken question.

"Which one of the following, if true, would most weaken the argument?"

Answer:  People who have nuts will always flex them. Since the Boys' argument contains an assumption, it is vulnerable to attack. An opponent could devastate the Boys' argument if she could prove that people who have nuts do flex.

OK, here's your homework. Same song, different verse:

Real gangsta-ass niggas don't talk much  All ya hear is the black from the gun blast  And real gangsta-ass niggas don't run for shit  'cause real gangsta-ass niggas can't run fast  

Focus on the last two lines. "Gangstas don't run for shit, cause gangstas can't run fast." What's the evidence? What's the conclusion? What's the missing piece? How would you answer a Sufficient Assumption question based on this argument? A Necessary Assumption question? A Weaken question?

 

 

 

 

 

An LSAT lesson from Dr. Dre

My favorite song is Let Me Ride, from Dr. Dre's studio debut The Chronic. (Jesus Christ, was that really 1994?!) There's one verse which I use to teach an important concept about necessary conditions... the fact that there can be many of them simultaneously. Seriously... I say this in class. It's a good one!

Dre's in his lowrider, picking up girls. (As usual.) He's on his way to a party, but he's got some important business to take care of first:

But before I hit the dope spot I gotta get the Chronic The Remy Martin and my soda pop

Count the necessary conditions:

1)  The Chronic. Obviously it's not a party without that.

2) The Remy Martin. Classy dude.

3) My soda pop. Oh, he's cutting it with soda? If I were him, I'd buy cheaper booze.

So here's the LSAT lesson: All THREE of these things are necessary. The failure of any one of these conditions can keep Dre from the party. No Chronic? No party. No Remy Martin? No party. No soda pop? No party.

And it's really important to understand that these three things are necessary, but not sufficient. Even if he does have all three of these things, Dre still might not go to the party. There could be other, unmentioned, necessary conditions: Perhaps he's also got to swing by and pick up Snoop Dogg, for example. And he definitely has to avoid getting gatted on the way. Etcetera. So all we know for sure is that if he does make it to the party, he'll be packing all three of these things. If he's lacking any of them, he won't be there. And even if he does have all three of them, he still might not make it. That's what "necessary" means.