Q23 - To be horrific, a monster

[dayme11]

I was between A and E. I ended up choosing A instead can you please explain why it is not A. Isn't it a condition that for a monster to be horrific it must be threatening?

[aileenann]

Sure! I would first diagram this argument as below:

Horrific -> threatening
Physical dangerous -> threatening (regardless of how)
Benign monster that inspires revulsion -> horrific

If you picked (a), you mixed up the logic, essentially reversing the first premise as listed above. But just because H->T doesn't necessarily mean that T-> H. The only thing we know if

H->T

is the contrapositive, namely

not T -> not H

Hopefully this sounds familiar from your Atlas strategy guides or some other LSAT book. If it doesn't, you should definitely get a guide to take you through this concept.

As to why the right answer, (E), is correct, look at the last premise of the argument. If you think about it, (E) is just a sub-case of that last premise - that is a specific elaboration of the general principle they give us as a premise.

I hope this helps! This is a great example of where conditional logic can be handy on the LR section as well as on LG. Hope to see you around the forum, and please do follow up if you have more questions or thoughts on this one.

[shodges]

I don't understand E.

My confusion comes from the addition of another condition seemingly out of the blue.

"All monsters that are not physically dangerous, but that are psychologically dangerous and inspire revulsion, are threatening"

I get how Revulsion } Horrific } Threatening works for one condition, but I don't get how they can just put in psychologically dangerous as a new condition not specifically mentioned in the stimulus and then say that ALL MONSTERS that are psychologically dangerous as well inspire revulsion.

The only thing I can think of is that the stimulus says "whether or not", seemingly indicating that the "psychological" condition doesn't matter if it's met or not.

Help is appreciated

[timmydoeslsat]

Since this a must be true type of question with logical cue words, it is a great idea to diagram this thing out and see what we can conclude from this.

Horrific ---> Threatening

Monster Phys Dangerous ---> Threatening

~Monster Phys Dangerous that inspires revulsion ---> Horrific ---> Threatening


Answer choice E tells us: All monsters that are not physically dangerous but are psychologically dangerous and inspire revulsion, are threatening.

So, do we know anything about a ~Monster Phys Dangerous that inspires revulsion? Yes we do! They are horrific, which leads us to threatening!

The psychologically dangerous part does come out of nowhere in this answer choice.

However, we know what happens when we have a monster that is not physically dangerous and inspires revulsion. That triggers threatening.

We could have had this as an answer choice:

All monsters that are not physically dangerous but are huge Justin Beiber fans and inspire revulsion, are threatening.


We can still reach the necessary condition of threatening due to the fact that we know two things from this hypothetical situation: 1) Monster is not physically dangerous 2) inspires revulsion.

[ManhattanPrepLSAT1]

haha... nice work Timmy!

[samuelfbaron]

I think there is a lot in this argument we can ignore. I ignored the "psychological, moral, or social dangers... infantile fears" part. I am not even sure if the 'physically benign' part has any bearing on the conditional relationship 'inspires revulsion --> horrific'.

Horrific --> Threatening

Physically Dangerous --> Threatening

Inspires revulsion -- > Horrific

We can simply connect the logic chain.

Inspires revulsion --> Horrific --> Threatening

For (E) all you really need to see is the 'inspires revulsion'. That will trigger the logic chain. Correct me if I'm wrong but the 'physically dangerous/psychologically dangerous part' of answer (E) has not affect on the conditional relationship at work here.

[aradunakhor]

When the passage says 'Even a physically benign monster is horrific if it inspires revulsion', can we take this to mean that:

inspires revulsion -> horrific,

ie that any monster that inspires revulsion is horrific?

The use of the word 'even' certainly suggests that interpretation, but the wording definitely made me pause for a bit to think it through.

[emily315]

could someone answer how does
"to be horrific. a monster must be threatening"
translates into the diagram of
horrific->threatening?

cuz I got
threatening-->horrific

[ohthatpatrick]

To be A, you must be B
will always translate into
A --> B

The conditional arrow can be read as the word 'requires'
A -----> B = A requires B


To get into law school, you must have an LSAT score.

If you got into law school, I'm certain you had an LSAT score.

I cannot say

If you have an LSAT score, I'm certain you got into law school.

You can remember that any time you're reading a sentence that means "one thing is required for another thing to be true", that
Req'd = Right side

(the right side of a conditional statement is, after all, called the 'necessary' condition)

Hope this helps.

[Laura Damone]

Question Type: Inference (Must Be True)

Stimulus Breakdown:

Horrific --> Threatening
Physically Dangerous --> Threatening
Inspires Revulsion --> Horrific (regardless of physical danger status)

There's a lot of fluff in this stimulus, so it really pays to strip it down to the bare logical bones. The types of physical dangers that a monster might present are irrelevant to the conditional logic.

To prephrase, we can chain the the statements:

Inspires Revulsion --> Horrific --> Threatening
                      Physically Dangerous --^


Correct Answer: E

A: Illegal Reversal of statement 1.
B: Illegal Negation of statement 3.
C: Illegal Chain. The only way to conclude a monster isn't horrific is by establishing that it isn't threatening.
D: Illegal Chain. Fulfilling the necessary conditions of threatening and horrific definitely doesn't negate the sufficient condition of inspiring revulsion!
E: Bingo. It can be tricky to see because of all the fluff, but as long as we establish that a monster inspires revulsion, we can conclude that it is both horrific and threatening, regardless of anything else.

Takeaway: Questions like this are meant to be diagrammed because that strategy forces you to get rid of the stuff that doesn't matter and look at the bare logical bones of the argument. Do yourself a favor and put pencil to paper right away on a Conditional Must Be True Inference question!

#officialexplanation