LSAT 148 | Section 4 | Logical Reasoning: Q21

LR Question 21 Explanation

QUESTION TEXT: Critic: To be a literary classic a book must reveal…

QUESTION TYPE: Must be True

FACTS:

1. Literary classic ➞ reveal something about human condition
2. Not worthy of serious study ➞ reveal something about human condition

ANALYSIS: This is a classic conditional chain. The argument has given us two conditional statements. If you take the contrapositive of the first statement, you can chain them together, like this:

1. Not worthy of serious study ➞ reveal something about human condition ➞ Literary classic

So, we can conclude that if something isn’t worthy of serious study, then it is not a literary classic. You can also take the contrapositive of the whole chain. That’s what the right answer does: literary classic ➞ reveal something about the human condition ➞ worthy of serious study.

___________

1. This is the incorrect negation of the deduction from the analysis above.
2. CORRECT. See the analysis above. If we join both statements together, we get a longer chain which has this as a conclusion.
3. This is actually a quantity statement. It’s saying “literary classics worthy of serious study do not exist”. Whereas a conditional statement would say they cannot exist. The stimulus only had conditional statements. Further, this answer contrasts with this statement we deduced in the stimulus: “If there are literary classics, then they’re worthy of serious study”
4. In the stimulus we showed “classic ➞ reveal ➞ worthy study”. This answer is very similar to an incorrect reversal of the final statement. Suppose I say “all cats have tails”. Is it possible that there are things with tails that aren’t cats? Yes. But can we prove it just using the “C ➞ T” statement? No. That’s what’s wrong with this answer.
5. This is exactly the same answer as D. If you view the chain as A ➞ B ➞ C, then D said “Some C not B”, and E says “Some B are not A”. See answer D for the full explanation, but if you have A ➞ B, then you can’t prove “some B are not A”.

Recap: The question begins with “Critic: To be a literary classic a”. It is a Must be True question. To practice more Must be True questions, have a look at the LSAT Questions by Type page.