LSAT 105 – Section 4 – Question 08

LSAT 105 - Section 4 - Question 08

February 1999

You need a full course to see this video. Enroll now and get started in less than a minute.

Ask a tutor

Target time: 1:22

This is question data from the 7Sage LSAT Scorer. You can score your LSATs, track your results, and analyze your performance with pretty charts and vital statistics - all with a Free Account ← sign up in less than 10 seconds

Question
QuickView		 Type Tags Answer
Choices		 Curve Question
Difficulty		 Psg/Game/S
Difficulty		 Explanation
PT105 S4 Q08
+LR
Flaw or descriptive weakening +Flaw
A
2%
156
B
91%
166
C
3%
158
D
2%
158
E
2%
160
130
141
151
 +Easier 144.839 +SubsectionEasier

Linguist: Only if a sentence can be diagrammed is it grammatical. Any grammatical sentence is recognized as grammatical by speakers of its language. Speaker X’s sentence can be diagrammed. So, speaker X’s sentence will be recognized as grammatical by speakers of its language.

Summarize Argument
The linguist concludes that speaker X’s sentence will be recognized as grammatical by speakers of its language. As premises, he gives three claims:

(1) If a sentence is grammatical, it is diagrammable.

(2) If a sentence is grammatical, it will be recognized as grammatical by speakers of its language.

(3) Speaker X’s sentence is diagrammable.

Identify and Describe Flaw
The linguist mistakes sufficiency and necessity. He assumes that because speaker X’s sentence is “diagrammable,” it is also “grammatical,” and therefore “recognizable.” But “grammatical” is the sufficient condition for “diagrammable,” not the other way around. Perhaps speaker X’s sentence is “diagrammable” but is not grammatical, and is therefore not “recognizable.”

In other words, he draws a conditional connection between “diagrammable” and “recognizable” when no such connection exists.

A
most people are unable to diagram sentences correctly
This wouldn’t damage the argument, so overlooking it can’t be a flaw. Even if most people can't diagram a sentence correctly, it doesn't affect whether the sentence can be diagrammed.
B
some ungrammatical sentences are diagrammable
This points out the linguist’s key flaw. He draws a conditional connection between “diagrammable” and “recognizable” when no such connection exists. It could be that speaker X’s sentence is diagrammable but is ungrammatical. In that case, the conclusion would fall apart.
C
all sentences recognized as grammatical can be diagrammed
If this were true, it wouldn’t impact the linguist’s argument either way. His argument rests on the mistaken assumption that all sentences that can be diagrammed can also be recognized as grammatical, not the other way around.
D
all grammatical sentences can be diagrammed
The linguist doesn’t fail to consider this. In fact, it’s just restating his first premise: “only if a sentence can be diagrammed is it grammatical.”
E
some ungrammatical sentences are recognized as ungrammatical
The linguist’s argument only states that all grammatical sentences can be recognized as grammatical. Whether some ungrammatical sentences are recognized as ungrammatical is not relevant.

Take PrepTest

Review Results

LSAT PrepTest 105 Explanations

Section 1 - Logical Reasoning

Section 2 - Logical Reasoning

Section 3 - Reading Comprehension

Section 4 - Logical Reasoning

Get full LSAT course

Leave a Reply