Q8 - Marcia: Not all vegetarian diets

[mit311]

Why is the correct answer A and not B or D.

[ManhattanPrepLSAT1]

This question is a classic example of a flaw typically referred to as a strawman argument. It is called that because the second speaker puts words into the first speaker's mouth, creating a straw argument - one that is easy to tear down.

Never does Marcia claim that vegetarianism cannot lead to nutritional deficiencies. Instead Marcia claims that not all vegetarian diets do lead to nutritional deficiencies - very different.

Answer choice (A) best reflects the flaw that Theodora is committing a flawed strawman argument.

(B) is not true. Theodora's conclusion would not be challenged by the research cited by Marcia.
(C) is not assumption of the argument.
(D) is a common flaw on the LSAT, but just not occurring here. The term "diet" is not used in two different meanings. In both cases it refers to the food consumed by individuals.
(E) is not an assumption of Theodora's argument.

Does that help clear this one up?

[goriano]

Marcia states: "Not all vegetarian diets lead to nutritional deficiencies"

If Theodora had instead stated "You are wrong in claiming that vegetarian diets cannot lead to nutritional deficiencies"

Would (A) still be the correct answer choice?

I ask because I'm trying to determine whether

"SOME vegetarian diets DON'T lead to nutritional deficiencies" (what Marcia is saying)

and

"SOME vegetarian diets DO lead to nutritional deficiencies" (what Theodora is saying)

can be properly construed as the same argument.

[ManhattanPrepLSAT1]

Sorry... but I don't quite understand your question.

If Theodora had instead stated "You are wrong in claiming that vegetarian diets cannot lead to nutritional deficiencies"

How is this different than what Theodora did in fact say?

"SOME vegetarian diets DON'T lead to nutritional deficiencies" (what Marcia is saying)

and

"SOME vegetarian diets DO lead to nutritional deficiencies" (what Theodora is saying)

can be properly construed as the same argument.

To this question, we cannot say that they are the same argument, but we can say that they are consistent arguments. While they both could be true at the same time, they have different meanings. The former implies that something less than all vegetarian diets lead to nutritional deficiencies, but this could mean that none do. The latter implies that at least some diets do lead to nutritional deficiencies, but this could mean that all do. So while these two claims are consistent with each (meaning they both could be true at the same time), the boundary of each claim is not overlapping.

Hope that helps!

[goriano]

Sorry... but I don't quite understand your question.

If Theodora had instead stated "You are wrong in claiming that vegetarian diets cannot lead to nutritional deficiencies"

How is this different than what Theodora did in fact say?

If I recall correctly, Theodora had said "You are wrong in claiming that VEGETARIANISM cannot lead to nutritional deficiencies"

So, are we supposed to equate VEGETARIANISM with VEGETARIAN DIETS? Thanks!

[ManhattanPrepLSAT1]

You're right, now I understand your question. And my response is a pretty good indicator that yeah, it's fair to equate vegetarianism with vegetarian diets.

I know! So frustrating! You wonder sometimes, can someone be a vegetarian without eating a vegetarian diet? I think it's fair to say that a vegetarian eats a vegetarian diet and someone who eats a vegetarian diet is a vegetarian.

My general rule of thumb is that early in the section, I give the test writer a lot of flexibility on language, but later in the section, I get pickier on language.

[goriano]

Thank you, for the response.

Earlier you had stated:

Never does Marcia claim that vegetarianism cannot lead to nutritional deficiencies. Instead Marcia claims that not all vegetarian diets do lead to nutritional deficiencies - very different.

So, since you are in fact equating vegetarianism and vegetarian diets as synonymous, the word switch is not itself the flaw. And so my previous question about

"SOME vegetarian diets DON'T lead to nutritional deficiencies" (what Marcia is saying)

and

"SOME vegetarian diets DO lead to nutritional deficiencies" (what Theodora is saying)

being different statements actually gets to the heart of the flaw, correct? I just want to confirm this reasoning so I can better recognize how highly nuanced the LSAT is. Thank you for being patient with my follow up questions!

[ManhattanPrepLSAT1]

And so my previous question about

"SOME vegetarian diets DON'T lead to nutritional deficiencies" (what Marcia is saying)

and

"SOME vegetarian diets DO lead to nutritional deficiencies" (what Theodora is saying)

being different statements actually gets to the heart of the flaw, correct?

Yes it does. Since those ideas are different, Theodora's reply is flawed because she attempts to undermine a claim different than the claim Marcia actually made.

Nice work goriano!

[nflamel69]

Can any instructors clarify this for me?

Can we interpret the flaw as that theodora is essentially arguing for a different group than marcia is, therefore its directed disproving a different claim? I interpreted that marcia is talking about the deficiency for the people who are following vegan diets, but theordora is talking about the deficiency for those people who are affected by those people who are following the vegan diets? (which I totally think is a ridiculous argument)

[wj097]

Can any instructors clarify this for me?

Can we interpret the flaw as that theodora is essentially arguing for a different group than marcia is, therefore its directed disproving a different claim? I interpreted that marcia is talking about the deficiency for the people who are following vegan diets, but theordora is talking about the deficiency for those people who are affected by those people who are following the vegan diets? (which I totally think is a ridiculous argument)

This is the same Q I want to ask to the instructors.
Can this also be a flaw in addition to the correct answer of this Q?
I would appreciate a quick reply.

Thank you.

[ohthatpatrick]

You know, I never read the rest of Theodora’s argument. As soon as I saw Theodora’s first sentence, I went to the answer choices. But now that you’re forcing me to read it, it IS awesomely stupid.

Yes, I think LSAT would consider her response a flawed obfuscation (distortion) of what Marcia was arguing.

Let’s change Marcia’s first claim so that it matches Theodora’s response:

Marcia: Vegetarian diets cannot lead to nutritional deficiencies.

Technically, this claim does not restrict itself to the group of [those who are eating the vegetarian diet].
So, technically, Theodora’s response is relevant to the claim of whether “vegetarian diets can ever lead to nutritional deficiencies”.

But in the context of Marcia’s entire argument (i.e. bringing in her premise), it’s clear that Marcia is using “lead to” in the context of “whether eating a veggie diet leads to the eater being malnourished”.

Meanwhile, Theodora is using “lead to” in the sense of “whether people eating veggie diets could ever set off a chain of events that culminates in someone being malnourished”.

So the correct answer could potentially be that Theodora’s response “trades on an ambiguity in the idea of ‘leads to’.”

I hope Theodora is not a practicing lawyer.

[ottoman]

I thought Theodora did ignore the research.
But A is clearly a better AC....

[VendelaG465]

How would I rephrase answer choice C? I had a hard time making sense of it...

[ohthatpatrick]

takes for granted
presumes, without providing justification
assumes, without warrant
and
fails to establish

are common beginnings of Flaw answer choices. They all mean the exact same thing: the author assumed _____ .


"Unless" is a common conditional trigger, and one way you can memorize diagramming it is to always replace it with the words "if not".

Let's take a sec to clean up "no meat-based industries will collapse unless most people become vegetarians" into an "if, then" conditional.

IF NOT most people become vegetarians, then no meat-based industries will collapse.

Cleaning up the IF NOT, we'd have:
If most people don't become vegetarians, no meat-based industries will collapse.

So you get that "unless" conditional into the more discernible "if, then" format, and then you ask yourself,
was this author assuming that if most people don't become vegetarian, then NO meat-based industries will collapse?

Your brain should already see some red flags: in Necessary Assumption, we're constantly wary of accusing the author of assuming something stronger than she needed to.

"most" and "NO meat-based industries" are both very strong.

If we look at the argument, Theodora is assuming that
"if most people DO become vegetarians, MANY meat-based industries will collapse."

It would be an illegal negation of her thinking for us to accuse her of assuming that
"if most people DON'T become vegetarians, ZERO meat-based industries will collapse."