#18 - Moderate exercise lowers the risk of blockage of the

[SherryZ]

Dec 2001 LSAT, Sect 1, LR, Q18:

My understanding to this question is:

Premises:
Lower Cholesterol lower hardening arteries lower arterial blockage;
Moderate exercise lower arterial blockage.

Conclusion:
Moderate ex lower cholesterol

So I was trying to find the connection, but I failed.

I chose C but the correct choice is D. Could you point out my error above and explain why D is right and C is wrong?

Thank you so much!

----Sherry

[Lucas Moreau]

Hello, Sherry,

Unfortunately, you slightly mis-identified the conclusion of this argument. The conclusion is actually the first sentence: "Moderate exercise lowers the risk of blockage of the arteries due to blood clots[...]" Thus your diagram works perfectly if you simply swap out your second premise and the conclusion. I know these can get confusing!

As for D, the correct answer choice to a Justify the Conclusion question will always fit the format:

"If [correct answer choice], and [premises in stimulus], then [conclusion of stimulus]."

So as you can see, the correct answer will be a sufficient condition to the conclusion's necessary condition. This stimulus even gives you the answer in its own language: "if the data reported in a recent study are correct[...]" If that's true, as D tells us, then the argument is complete.

Hope that helps,
Lucas Moreau
PowerScore

[ltowns1]

Hi. I have a quick question about the “if the data is true” part of the stimulus. I misidentified the conclusion as being the last sentence and not the first. As a result I thought that the data being true part was taken as a given . Had that been a part of the conclusion, the data part would have to be assumed true, correct?

[Adam Tyson]

We never have to assume that a Sufficient Condition occurs, ltowns1, even if that Sufficient Condition is a part of a conditional conclusion. I might conclude, after presenting some evidence, that if I eat a large meal, then I will take a nap afterwards, but that only proves that the nap would be guaranteed IF I eat the large meal. It would not prove that I DID eat a large meal, and therefore doesn't prove that I WILL take a nap.

Accepting a conditional premise means only that we accept that IF the sufficient condition occurs, THEN the necessary condition must also occur.

[ltowns1]

Understood, would you agree that normally though on the LSAT, in a conditional conclusion, what is usually being undermined is how the necessary condition doesn’t follow from the sufficient?

[Rachael Wilkenfeld]

It totally depends on how it's used, ltowns. To negate a conditional statement, you say the sufficient occurs but the necessary does not. Typically, when we undermine conditional chains, we say that one of the sufficient conditions didn't occur. That would mean that we couldn't conclude the necessary condition occurred. Those are all within the normal logic of conditionality. We don't typically take the conditional as given and say that it isn't true. We use logic and reasoning to undermine the conclusion.

For example, let's look at a simple example.

All men are mortal. If Socrates is a man, then Socrates is mortal.

To weaken or undermine that conclusion (Socrates is mortal), we'd attack the sufficient condition. We'd say that Socrates is not a man. We wouldn't say that Socrates is a man, but the conclusion doesn't follow. We don't argue with the facts as given. We focus on what we can deduce from the facts.

Hope that helps!

[ltowns1]

Thanks so much Rachael