Q20 - Researcher: We have found that

[lianghuang98]

The correct answer is E. My choice is D.

Negate the D: some conditions that are treated effectively by medicine are also treatable through the reduction of stress.

Then some high blood pressure can be treated effectively with medicine -> it can be treated through reduction of stress -> high blood pressure can be caused by stress.

This will hurt the conclusion: high blood pressue must not be caused by stress.

I think D is wrong because it did not mention 'high blood pressue', it only say 'some condition'.

Am I correct?

[aileenann]

Hello!

I would question your statement of the conclusion. Remember, generally the conclusion is something we can basically cut and paste from the argument itself. HEre, we can see that the conclusion is actually somewhat more limited that you state. It is "*some* cases of high blood pressure must not be caused by stress." Now, I think if you negate the answer you will find that it destroys this conclusion.

I hope that helps! Let me know if you have any follow up questions.

[lianghuang98]

Hello, aileenann:

Thank you for replying.

I probably did not type all the words in the conclusion to include 'some'. But I fully understand that 'E' is the correct answer by negating it to see it hurt the conclusion.

What I am not quite sure about is why D is incorrect? Is it because of the reason I stated in my previous post?

[aileenann]

Thank you for clarifying. I am sorry I did not understand your original question.

I would say the most direct reason that (D) is not the answer is that (D) actually restates a premise, albeit in somewhat reworded form, and a premise cannot be an assumption. A premise must be unstated. Here, (D) is stated as a premise in the form of "it is generally accepted that any illness caused by stress is treatable only by the reduction of stress," which is the same as saying that an illness treatable by stress reduction probably cannot be treated by medicine, which is virtually the same as the statement in (D).

I hope this answers your question. Again, please do feel free to follow-up!

[ManhattanPrepLSAT1]

To understand this one we need to see that the argument in the stimulus is fairly strong. If some cases of high blood pressure can be treated effectively with medicine and (taking the contrapositive of the second statement) any illness that is treatable by something other than the reduction of stress is not an illness caused by stress. It must follow that some cases of high blood pressure are not caused by stress.

There is not much of a gap here. The only thing we need to ensure is that the cases of high blood pressure that are treatable with medicine do not in fact reduce stress. If they did, then the second premise would no longer apply and the conclusion wouldn’t follow. What we need to ensure is expressed in answer choice (E).

(A) is not assumed. The correlation does not need to be coincidental. The correlation could be the result of some other causal relationship of which they are both a product.
(B) goes against the conclusion by saying that there is potentially a causal relationship between stress and high blood pressure.
(C) is irrelevant. Even if reduced stress did reduce a person’s responsiveness to medicine used to treat high blood pressure, the argument would not be any weaker. The argument is about whether some cases of high blood pressure are caused be stress, not whether a reduction in stress inhibits responsiveness to medicine.
(D) is not necessary. They’re not saying that high blood pressure is not treatable by the reduction of stress. They’re just saying that high blood pressure is not caused by stress. So, even if everything treated effectively with medicines were also treatable through the reduction of stress, the argument would still stand.
(E) is necessary for the conclusion to stand. If medicine used to treat high blood pressure does itself reduce stress, then the second premise no longer applies and the conclusion falls apart.

[noah]

I've been preparing this question for a student that I'm tutoring and it's really giving me a headache, so I figured I'd write out an explanation to help me clarify the question for myself before teaching it.

The conclusion of this argument is that there are some cases of high blood pressure (HBP) that are not caused by stress. Why? Because if a condition is caused by stress, it is only treatable through stress reduction. And, it turns out that HBP is treatable with medicine.

This is an assumption question, so it's helpful if we can find a gap. Here's if we remove the last line above (one of the premises) and imagine what we think it should say, we might write this: "And, it turns out that HBP is only treatable with stress reduction, not medicine." But instead, the argument only tells us it is treatable with medicine, and it leaves it up to us to think (assume!) that this means medicine is not a way to reduce stress. (E) states this assumption clearly. If we were to negate (E), it would state that medicine is a way to reduce stress, and then it wouldn't make sense to conclude that there has to be some HBP cases not caused by stress, because those cases that are caused by stress could be treated with the stress-reducing medicine.

The wrong answers (and here's where the headache ensued!):

(A) is tempting, but it is essentially irrelevant -- the argument does not require the connection to be coincidental. In fact, if anything, the argument requires there to be some meaning to the connection. If it were coincidental, then how could we conclude much about it?
(B) is tempting as well -- but the argument does not discuss whether stress reduction is effective or not. The matter at hand is not whether stress reduction is effective. While the efficacy of medicine is mentioned, the argument does not depend on stress reduction working or not to treat HBP.
(C) is out of scope - reduced responsiveness?
(D) is extremely tempting -- I can see why the OP (original poster) chose it. It's tempting because it mentions medicine and reduction of stress, the issues that need to be linked by an assumption. However, the link (D) establishes is that some illnesses for which medicine is a treatment are not treatable through stress. Stress reduction may or may not work for random illnesses -- we've been told, though, that it is the only treatment that will work for illnesses caused by stress. Who cares if there are some illnesses out there for which only medicine works? As Aileen mentioned above, (D) is also suspicious because even if it were about stress-caused illnesses, it would essentially be a premise booster.

To make an analogy -- here comes the second headache:

Some dogs can only be trained by professionals. Since we all know that dogs whose owners have high voices can only be trained by people with high voices, it must be that some dogs do not have owners with high voices.

and to make it a bit clearer:

Some cats must have fish to be happy. Since we all know that cats with white tails must have eat white food, there are some cats without white tails.

Why? Because I'm assuming that fish isn't white. Read it with the assumption:

Some cats must have fish to be happy. Since we all know that cats with white tails must have eat white food, and so they have to be eating something other than fish, since fish can't be white, and so there are definitely some cats without white tails (the cats eating that has-to-be-something-other-than-white fish).

If it helps you to see the diagram for an argument, which I don't think this question requires to solve in real time:

some HBP --> medicine to treat
stress-caused illness --> stress-reduction to treat
[contrapositive] ~ stress - reduction to treat --> ~ stress-caused illness
Therefore: some HBP --> ~ stress-caused illness

This works if we have medicine to treat --> ~ stress-reduction, because then we could say:

some HBP --> medicine to treat --> ~ stress - reduction --> ~ stress-caused illness

I hope that cures my headache and yours!

[bnuvincent]

Hi, I still don't understand why D is wrong, in the stimulus it states
illness by stress --> reduction of stress,
so if combined with what D says, we get that illness are not by stress, the conclusion of the stimulus.

Could you please explain?

[ManhattanPrepLSAT1]

Are you approaching this question from the perspective of a Necessary Assumption or that from a Sufficient Assumption. You're not looking to add something that will allow the conclusion to be properly drawn. You're looking to find something that is required in order for the conclusion to have even a chance of being true.

Taking a closer look at (D)...

Had it read "Some conditions treatable through the reduction of stress are not effectively treated by medicine," the answer would have been better.

Good question!

[ahnhub]

Here's how I approach eliminating D:

The argument says any illness caused by stress is treatable "only" through stress. D is making the assumption that some conditions that can be treated by medicine are not "also" treatable through stress reduction. That is not necessary to the argument because that condition does not conform to the premise, which states that anything caused by stress can be treated only through the reduction of stress, not that reduction of stress must be one of various ways to treat a condition caused by stress.

This is a very strong argument, and the only real assumption it makes is that the medicine isn't working by reducing stress.

By the way, I chose E too

[nflamel69]

I think the difference between D and E is quite subtle. Like many posters already suggsted, we need to say that the medicine is not working by reduction of stress. E is clearly right. The reason D is wrong is because of the phrase "are not also treatable". We don't need to assume this, we only need to assume medicine is not reducing stress. there's a difference between treating by not reduction of stress and not treatable by reduction of stress.

[micpar]

I had a quite a bit of trouble with (D) as well.

The key here is the premise that states that illnesses caused by stress may only be treated through stress reduction. Let's think about this for a second:

If I have High Blood Pressure caused by Stress then the only way get cure my High Blood Pressure would be reduce my Stress. But what if my High Blood Pressure was caused by something else, like a congenitally bad heart? Then the illness could be treated by any number of things, and not just stress reduction, right? It could even be the case that my High Blood Pressure could be treated by Stress Reduction and Medication as well.

Let's look at this latter scenario alongside the negation of (D):

If a condition is treated effectively by medicine then it also is treatable through stress reduction.

This only really poses a problem if we assume that this HBP was caused by stress but according to our scenario (a case of HBP not caused by stress, but capable of being treated by both), we don't have to assume that it was, do we?

The conclusion is making the argument that there are are some cases of HBP that must not be caused by stress because they are treated by medication. The negation of (D) doesn't pose a problem because we could just be talking about a type of HBP not caused by stress, but that could be treated through the reduction of stress

The key is to really internalize the fact that we aren't talking about one type of high blood pressure and realizing all the implications of the causal rule put forward in the stimulus.

[ttunden]

I am not sure about the restating premise part however with D, it is for sure too ambiguous.

"some Conditions'?

how do we know that "some conditions" = some cases of high blood pressure? That's the main problem with D. I was down to D and E and luckily picked E. I thought it may have been too strong for a necessary assumption question but if you negate it, it destroys the argument.

So, that's the main problem with D. We don't know if the some conditions are some cases of high blood pressure. Those "some conditions" could be high cholesterol, sleep anxiety, anger issues, depression, etc.

[christine.defenbaugh]

I am not sure about the restating premise part however with D, it is for sure too ambiguous.

"some Conditions'?

how do we know that "some conditions" = some cases of high blood pressure? That's the main problem with D. I was down to D and E and luckily picked E. I thought it may have been too strong for a necessary assumption question but if you negate it, it destroys the argument.

So, that's the main problem with D. We don't know if the some conditions are some cases of high blood pressure. Those "some conditions" could be high cholesterol, sleep anxiety, anger issues, depression, etc.

I love the way you're getting specific with the language, ttunden!

However, I'd caution you about using "ambiguity" to knock out an answer on a necessary assumption question. Ambiguity is actually kind of awesome for necessary assumptions - the more vague the answer choice, the more likely we are to need it. Ambiguity is essentially the same thing as "weak language".

We don't know what those 'some conditions' are, or whether they are HBP, but that's not the problem here. Consider this argument:

PREMISE: All poisonous things glow in the dark
CONCLUSION: Therefore, some apples glow in the dark.

A necessary (and sufficient) assumption for this argument is that some apples are poisonous. However, we could make a necessary assumption that is way more ambiguous: some fruits are poisonous. We don't know that the fruits in question are apples, but that's okay - we still need this broader version of the statement to be true. After all, if ZERO fruits are poisonous, then our argument is doomed.

The ambiguity is not the problem with (D).

Let's lay out the argument core to be completely clear:

PREMISE:
1) Some HBP are treatable w/ medicine
2) If stress-caused condition --> condition treatable only with stress-reduction
CONCLUSION: Some HBP are not stress-caused

First, let's be careful to note the contrapositive of that conditional premise:

If condition treatable by anything other than stress-reduction --> condition is not stress-caused

It's this contrapositive of the premise-conditional that would successfully get us to the conclusion....if only we could trigger it for some HBP.

(D) seems like it makes the connection to the contrapositive-conditional possible, at first glance. "Some conditions that are treated effectively by medicines" would potentially cover those HBP cases treated by medicine. In fact, if this answer had said "Some conditions that are treated effectively by medicines are treatable by something other than stress-reduction," then this would absolutely have been a valid necessary assumption.

But that's not what it said. Instead, (D) says that that broad category contains at least some conditions that are not treatable through stress-reduction. We don't need the HBP (or broader category) to be untreatable by stress-reduction to trigger that contrapositive above. We simply need the HBP (or broader category) to be treatable by something else that isn't stress-reduction.

The temptation of this answer choice really highlights the dangers of diagramming a conditional without fully understanding it. If we had diagrammed the original conditional as simply "if stress-caused --> stress reduction", then we would be unable to distinguish between "untreatable by stress-reduction" and "not treated by stress-reduction" (or "treatable by something other than stress-reduction"). We would mistakenly think both triggered the contrapositive. As a result, it would be impossible to distinguish (D) and (E).

Note that (E) here says that the HBP medicine doesn't reduce stress. And yet we know, from the premise, that it is effective in some cases. That must mean that the HBP is treatable through something other than stress-reduction. THAT will trigger the contrapositive of the premise-conditional!

To sum up - don't ever kill an answer on a necessary assumption question just because it's ambiguous. That's a hallmark of weak language, and that actually makes necessary assumption answers more likely to be correct. Instead, carefully evaluate the subject of the broad statement to make sure it actually connects the elements you need to connect!

What do you think?

[akrawls]

this problem tripped me up the first time around and then i spent another 15 minutes with my face in the book trying to sort out where i went wrong.

the good news is, i was finally able to make some sense of it all....

here's my reasoning:

conclusion: some cases...not caused by stress

after looking at premise 2 (which i'll get to shortly) it really means that all cases of high blood pressure (hbp) cannot be treated by reducing stress. (keep in mind this is the lsat there doesn't have to be any truth in order for there to be a valid argument).

why? because according to premise 2 high blood pressure, a stress related illness, can only be treated by reducing stress. essentially what this means is that the only way for an illness to be categorized as "stress related" is if it can be treated by "reducing stress".

in other words if reducing stress doesn't work in treating the disease then it isn't a stress related illness.

premise 1 tells us that medicine works and is effective in treating hbp.

therefore, if the medicine can effectively treat hbp then it must
not work by reducing stress.

if you use the negation technique and assume that it does work, then the conclusion that we arrived at "hbp cannot be treated by reducing stress" is blown up and badly weakened.

[stm_512]

If we think of premise 2 as: The reduction of stress is the necessary condition for an illness caused by stress being treatable, then we can clearly see why D) is wrong.

Illness caused by stress treatable -> Reduction of stress

But I guess I'm having trouble seeing why this interpretation of the conditional is incorrect: The state of being treatable only by the reduction of stress is a necessary condition for an illness caused by stress.

Illness caused by stress > Treatable only by the reduction of stress

If this interpretation is correct, then doesn't D) seem more attractive?

I think this underlies the source of my confusion, as well as other students.

[mimimimi]

If we think of premise 2 as: The reduction of stress is the necessary condition for an illness caused by stress being treatable, then we can clearly see why D) is wrong.

Illness caused by stress treatable -> Reduction of stress

But I guess I'm having trouble seeing why this interpretation of the conditional is incorrect: The state of being treatable only by the reduction of stress is a necessary condition for an illness caused by stress.

Illness caused by stress > Treatable only by the reduction of stress

If this interpretation is correct, then doesn't D) seem more attractive?

I think this underlies the source of my confusion, as well as other students.

First of all, thank you for typing it out. For a while, I could not even pinpoint why and where my thought process is so different from the explanations above. Yes, this is precisely where the confusion is. I literally spent two hours on this question, got so mad, quit, came back, still confused, quit, went to discuss it with someone else... but I finally made peace with myself and this is why:

How should we decipher the 2nd premise? -- Any illness caused by stress is treatable only by the reduction of stress.

The most prevailing interpretation of this premise is extensively discussed above:
Any illness caused by stress is treatable/ only by the reduction of stress.
Meaning: If an illness is caused by stress AND is treatable, then it is guaranteed that it is treated by reduction of stress.

The 2nd interpretation that confused us reads this way:
Any illness caused by stress is / treatable only by the reduction of stress.
Meaning: If it is an illness caused by stress, it is treatable only by the reduction of stress, not by something else but just by this one type of treatment.

Notice that if this 2nd interpretation is true, when combined with the first premise that some high blood pressure (HBP) is treatable by medicine, we get that reduction of stress treatment is not the only method to treat the HBP. So the HBP is not caused by stress - our conclusion! What is the flaw here? There is really none. Note that even if the HBP is also treatable by reduction of stress in addition to medicine, the conclusion will still hold. This is because we have two treatment methods for this illness now, not just only one by "reduction in stress." So what do we need to assume here then? Maybe that there actually exists some illness that can be treated with medicine? But we don't need to assume that, since it is ALREADY stated IN the first premise: some high blood pressure can be treated by medicine. The whole argument is actually valid using our 2nd interpretation.

Let's go back to (D): If something is treatable by medicine, by default it is not the only method, let alone the only method by "reduction in stress." (D)'s assumption is useless at best.

If you are not convinced, try to negate (D). We get:
There are no conditions that are treated effectively by medicines are not also treatable through the reduction of stress.
Meaning: There are some illness that can be treated both by medicine and reducing stress.

Guess what, our conclusion still holds. By definition, such dual treatments will defeat our reading of "only one type of treatment" for illness caused by stress, therefore it does not affect our original conclusion in any way.

To conclude, according to our confused 2nd interpretation, D is still wrong. In addition, I do not see how E can also be correct under this interpretation, so I have to believe that this is not the interpretation that the test writer had intended.

A side note: I don't know if this question was intended to be THIS confusing. The prevailing interpretation really makes the answer choices much more obvious and intuitive.

[asafezrati]

I'm having issues with some of the above posts, so I'll try it myself, in full.

Premises:
1. some HBP can be treated by medicine.
2. if (caused by stress) -> (can be treated by reduction of stress) + (cannot be treated by anything else)
[these two elements mean that stress reduction is the only treatment, and nothing else!]
The contrapositive of this is:
~(can be treated by reduction of stress) OR ~(cannot be treated by anything else) -> ~(caused by stress)

Conclusion:
some HBP are ~(caused by stress)

-----

We can expect these "some HBP" to be the ones that can be treated by medicine.
"can be treated by medicine" = ~(cannot be treated by anything else [other than stress])
and through the contrapositive of premise 2 we reach ~(caused by stress)

A little less formally this is what the author wanted to do:
some HBP -> treated by medicine -> ~(cannot be treated by anything else [other than stress]) -> ~(caused by stress)

-----

Answer Choices:

A. Undermines premise 2, very strong and unnecessary. It isn't even a sufficient assumption because it doesn't fill any gaps between argument's parts.

B. It's a strange one. I thought it was a premise booster, but its negated form tells us:
The reduction of stress CANNOT EVER lower (=treat?) that person's blood pressure (including HBP).
So if the medicine treated the HBP, while HBP can never be treated by lower stress, then according to premise 2 it must not be caused by stress.

C. Lower responsiveness to medicine doesn't necessarily destroy the effective treatment.

D. Obviously the toughest wrong A/C, as it negates the "other side of the OR" in the contrapositive, and it also includes weak language ("some") which makes it very appealing. But here's the thing: according to premise 2, if an HBP (illness) can be treated both by medicine and by reduction of stress then it isn't an illness caused by stress - because illnesses caused by stress can be treated ONLY by reduction of stress and NOTHING ELSE.

E. Seemed too strong to my taste, but apparently this is the only way the argument can work, and so it is necessary.

-----

The key here is not to screw up the meaning of the conditional. Even if you don't - it's tough.

[kimsara3]

After an hour of futile attempts to understand why D was wrong and E was right, I came upon your post and achieved the long awaited eureka moment. Conditional reasoning must be ingrained in my head because, despite your clever analogies, your outline of the conditional relationships finally helped me understand the answer to this problem. Thank you for taking the time to explain this problem, my headache as finally been cured!!!

some HBP --> medicine to treat
stress-caused illness --> stress-reduction to treat
[contrapositive] ~ stress - reduction to treat --> ~ stress-caused illness
Therefore: some HBP --> ~ stress-caused illness

This works if we have medicine to treat --> ~ stress-reduction, because then we could say:

some HBP --> medicine to treat --> ~ stress - reduction --> ~ stress-caused illness

I hope that cures my headache and yours!

[hayleychen12]

I have a question concerning E.

When negating it: Medicine used to treat high blood pressure does it self reduce stress.

I don't think it hurts the conclusion :some cases of high blood pressure must not be caused by stress.

I think it is not related to the conclusion anymore.

Maybe when using acupuncture to cure HBP, it does not reduce stress. We simply just don't know.

[JosephD183]

I have a question concerning E.

When negating it: Medicine used to treat high blood pressure does it self reduce stress.

I don't think it hurts the conclusion :some cases of high blood pressure must not be caused by stress.

I think it is not related to the conclusion anymore.

Maybe when using acupuncture to cure HBP, it does not reduce stress. We simply just don't know.

If medicine used to treat HBP did itself reduce stress, that would destroy the conclusion.

The conclusion is that some cases of HBP are not caused by stress BECAUSE some cases of HBP are treated effectively with medicine AND it is generally accepted that any illness caused by stress is treatable ONLY by the reduction of stress.

If medicine did itself reduce stress, you are unable to reach your conclusion that some cases of HBP are not caused by stress (because although medicine is effectively treating it, that could be through the reduction of stress).

D negated is:
"Some conditions that are treated effectively by medicines are also treatable through the reduction of stress"

Although this is a tempting answer, look at it strictly against the argument "some cases of HBP are not caused by stress because they are treated effectively with medicine and it's generally accepted any stress caused illness is treatable only through the reduction of stress".

This is simply restating the second premise "generally accepted that any illness caused by stress is treatable ONLY by the reduction of stress".