Q16 - In most of this forest

[ManhattanPrepLSAT1]

Question Type:
Strengthen

Stimulus Breakdown:
The argument concludes that in most of this forest the expected outbreak of tree-eating tussock moths should not be countered. Why? Well, the moth is beneficial where the forest is unnaturally crowded with immature trees.

Answer Anticipation:
To support this argument it'd be helpful to know that most of this forest is unnaturally crowded with immature trees.

Correct Answer:
(A)

Answer Choice Analysis:
(A) is correct. This provides the information to know that the rule is applicable to the given circumstance.

(B) undermines the argument. The rule seems to imply that it is the overcrowding from immature trees that is the problem.

(C) undermines the relevance of the example which suggests that the prevention of forest fires leads to an overcrowding of immature trees.

(D) is out of scope. Whether the expected outbreak is likely or not isn't relevant to whether it would be beneficial.

(E) is out of scope. Whether or not there are effective countermeasures would impact whether we could counter the expected outbreak of tussock moths, but not whether we should.

Takeaway/Pattern: Reasoning Structure: Conditional Logic

#officialexplanation

[andrewgong01]

How do we know in the argument that immature trees are "bad" and how do we know the moths are the ones that eat "immature trees" and not mature trees?
My pre-phase for this, based of the conclusion of letting the tussock moths stay in the forest was to establish that these moths eat the immature (or mature) trees because that is good for the forest. However, this was not in the answer choice and it seems like it was implied that immature trees are bad and that these moths do in fact eat immature trees and not mature trees.

I guess the good thing in this question is that C,D, E can be eliminated right away because they do not seem relevant to the core: Let the moths live. However, this leaves "A" and "B" and unfortunately if the question was interpreted in a way where mature trees are bad or mature trees should be eaten then "B" would be correct but it is the wrong answer.

[AyakiK696]

I guess I can see how, reading it through a second time, A makes sense as an answer... I'm still really confused about how I was supposed to approach this question, though. My prephrase was "the outbreak should not be countered because the moths will eat the immature trees." I didn't choose answer A because I thought it essentially said the same thing as the premise (what with stating that the forest is "unnaturally crowded with immature trees"), and that really threw me off. How should we approach this form of Strengthen questions?

[christine.defenbaugh]

Some good questions from both of you!

Two really important points:

• We do not actually need to establish or assume that immature trees are bad.


• We DO need to know whether there are too many immature trees in this particular forest

Both of these misunderstanding hinge on exactly what the premise does, and does NOT, already tell us.

the moth is beneficial where we have unnaturally crowded immature trees

This is a conditional statement. I don't need to know why moths are beneficial in that situation. The premise just tells me that they are. Real life tells me that, yeah, it's probably because the moth will munch on some of the young trees and cut down the crowding, but I really do not need to know that. Why? Because it's a conditional. It's a promise. If I'm in a forest unnaturally crowded with immature trees, then POOF-magic, that means moths are beneficial.

For all I know, it's because in that particular situation the moths barf rainbow beams that shine holy light on all forest life, turning the forest into an immortal sanctuary. Or not. Really don't care - I just know that somehow, some way, the moths are beneficial in that situation.

But what I don't know, at least not yet, is whether this situation (being unnaturally crowded with immature trees) is something that is actually happening in this forest. They never said that. They said that WHEN we have that crowding, moths are beneficial. But that's a general rule that could apply (or not) anywhere.

It's like if I argued:
When it is Tuesday, Mary goes to the gym.
Therefore, Mary will go to the gym today.

I can't know that the rule of the premises gets triggered today, unless I know that today is actually Tuesday.

This argument is:
When you have crowding of immature trees, moths are beneficial.
So, we should let the moths do their thing in this forest.

Well, if the moths are beneficial in this forest, then letting them do their thing sounds like a good idea. But to know that they are beneficial here, I need to know that we have that immature-tree-crowding situation that is the trigger for the premise-conditional.

And this goes to the heart of why (B) is wrong. Adding that information in means that 1) moths are beneficial when we have immature-tree crowding and 2) oddly, they eat the old ones first. Mmmm, okay, that's a strange set of behaviors, but regardless, nothing in that would give me any reason yet to think that we should let the moths do their thing in this particular forest.

Takeaway: Conditional-premises don't tell you that the conditional has actually been triggered. But they are promises that we can rely on, absolutely, once they are triggered - even if we don't fully understand why the conditional makes the promise that it does, it's still a promise we can trust.

[AyakiK696]

This clarifies so much for me and I think that takeaway is really something I needed to understand! I'm so glad I figured this out before I take the exam haha. Thank you so much!

[krisk743]

Question Type:
Strengthen

Stimulus Breakdown:
The argument concludes that in most of this forest the expected outbreak of tree-eating tussock moths should not be countered. Why? Well, the moth is beneficial where the forest is unnaturally crowded with immature trees.

Answer Anticipation:
To support this argument it'd be helpful to know that most of this forest is unnaturally crowded with immature trees.

Correct Answer:
(A)

Answer Choice Analysis:
(A) is correct. This provides the information to know that the rule is applicable to the given circumstance.

(B) undermines the argument. The rule seems to imply that it is the overcrowding from immature trees that is the problem.

(C) undermines the relevance of the example which suggests that the prevention of forest fires leads to an overcrowding of immature trees.

(D) is out of scope. Whether the expected outbreak is likely or not isn't relevant to whether it would be beneficial.

(E) is out of scope. Whether or not there are effective countermeasures would impact whether we could counter the expected outbreak of tussock moths, but not whether we should.

Takeaway/Pattern: Reasoning Structure: Conditional Logic

#officialexplanation

How is B out of scope....B implies the trees being a problem because the argument clearly displays a negative connotation on "unnaturally crowded with immature trees". I was searching for an answer to account for moth benefit plus dealing with the unnaturalness of these trees.

Not sure how you can read that statement quoted and think it isn't an issue.

[JAkeG658]

Here's my gripe with this question: I understand why A, if interpreted as intended by the LSAT, completes the passage logically. The problem is the ambiguity in the word "the" in the answer choice, which leaves us wondering if it is a continuation of the example, or a reference to the original forest.

The stimulus begins with "in most of THIS forest..." (we should not prevent the tree eating moths) and it the gives an example of when the moths are beneficial in THE forest when it is crowded with immature trees and _______

Answer choice A is worded using THE forest, which would lead us to believe it is a extension of the example, being another condition for which the moths are beneficial. This would not logically fill the blank because we could not possibly predict the set of conditions for the moths being beneficial, the stimulus is supposed to give us these. So, this completely warranted interpretation would make answer A incorrect.

If they used "this" instead of "the" in answer choice A, it would unambiguously be referring to the forest in question and not to the example mentioned. It would then be a solid answer because, given the single condition in the example, we would know that we meet that condition and the moths should not be suppressed.

[JohnD194]

I just feel like C is a premise booster. We know there are a lot of immature trees, it says in the stimulus. Can anyone explain C in relevance to it seeming like a premise booster?

[ohthatpatrick]

(C) is a premise booster in the sense of
- we already know we're talking about a hypothetical forest that is crowded with immature trees, so we don't need to hear more about the backstory of why the forest is crowded with immature trees (the fire thing was just an example, not a crucial component).

(C) is a undermining the premise, though, in the sense that it goes AGAINST the backstory in the example of why the forest is crowded with immature trees.

SUPPRESSING fires led to crowding with immature trees.
ALLOWING fires would cut down on the overcrowding of immature trees.

(C), however, makes it sound like allowing fires would cut down on the numbers of mature trees and lead to a higher proportion of immature trees.