LSAT 143 | Section 4 | Logical Reasoning: Q11

LR Question 11 Explanation

QUESTION TEXT: A development company has proposed building an…

QUESTION TYPE: Flawed Reasoning

CONCLUSION: The airport probably won’t be built.

REASONING: A sufficient condition for building the airport wasn’t met.

ANALYSIS: This is a terrible argument. Really horrible. Worthless.

I’m speaking so strongly because it sounds good. But all the argument has said is that we lack a sufficient condition for building the airport.

Lacking a sufficient condition has no effect. Here’s a parallel argument:

“If I’m the US President, people will want to talk to me. But I’m not President, so nobody will ever want to talk to me.”

The error is thinking that people will never talk to you unless a very narrow sufficient condition is met. But it’s possible people would talk to you for many reasons, and it’s possible there are other reasons the airport would be built.

___________

1. CORRECT. Something can happen for multiple reasons. Lack of a sufficient condition isn’t a problem. Only lack of a necessary condition is a problem.
2. The argument didn’t do this.
   Example of flaw: People believe in astrology. So astrology works.
3. The argument didn’t do this.
   Example of flaw: I probably won’t win the lottery. So it’s impossible for me to win the lottery.
4. It doesn’t matter what people living near Dalton think. We only know what happens if people in Dalton favor the proposal.
5. The fact that a project has a benefit doesn’t mean it will definitely happen. So the fact that the airport benefits the economy doesn’t tell us whether the airport will be built.