Can a necessary assumption correct answer attack premises?

izzy895
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Can a necessary assumption correct answer attack premises?

Postby izzy895 » Tue Oct 22, 2013 2:03 pm

I'm not sure if this has come up, if so I apologize. As the title says can a correct answer to a nec. Assumption attack premises? For example:

Mike goes to the store at 9... Then blah blah, therefore he has enough money to buy the food. Something along those lines.

Will a correct answer ever be something like, mike does not sleep past 9 o'clock? I'm trying to remember if there was a specific problem that had an issue like this. Sorry if the explanation is kinda bad, thanks.

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mindarmed
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Re: Can a necessary assumption correct answer attack premises?

Postby mindarmed » Tue Oct 22, 2013 2:27 pm

A necessary assumption question will look for an answer choice that bridges a gap in the argument. The gap can exist between two premises or a premise and the conclusion.

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PourMeTea
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Postby PourMeTea » Tue Oct 22, 2013 2:32 pm

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izzy895
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Re: Can a necessary assumption correct answer attack premises?

Postby izzy895 » Tue Oct 22, 2013 4:04 pm

I probably set that up wrong i couldn't think of a good example. The negation would show he couldn't of gone to the store at 9 because he would of been sleeping. If I just have things screwed up I'll take it that I shouldn't worry about this being an issue. Thank you for the response.

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PDaddy
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Re: Can a necessary assumption correct answer attack premises?

Postby PDaddy » Tue Oct 22, 2013 4:21 pm

The relationship between a (correct) necessary assumption and the argument to which it belongs is the same as the relationship between food and your body: negate the former and the latter dies. That means the correct answer to a necessary assumption - in its original form - should never kill an argument. It only strengthens, if only by a little bit in some cases.

Remember, an assumption question is a strengthen question, and the correct answer to a strengthen question can strengthen a little or a lot. The degrees to which those answers strengthen varies along an imaginable continuum.

In the same way that your body might still be deficient of certain vitamins, minerals and nutrients even while regularly eating enough to survive, an argument can still be weak after the plugging-in of the correct necessary assumption. The argument may or may not still have problems, or "logical gaps", but it will be helped by the assumption. What it will NOT be is a "flawed" argument (it never was to begin with), and that should allow you to rest assured that you have the correct answer.

Remember, there's a big difference between a flawed argument and a "deficient" one. Assumption questions address deficient arguments.

Necessary v. Sufficient:

After inserting a necessary assumption, the argument can still have problems, whereas the insertion of a sufficient assumption makes the argument seem perfect.

This is the main difference between the dynamics of necessary assumptions and their arguments v. "justify assumptions" (sufficient assumptions) and the arguments to which they relate. The correct answer to a sufficient assumption/justify question completely eliminates the main logical gap and makes the argument whole. It strengthens the argument in a way that it is very strong, with few or no holes, but it's negation does not necessarily kill the argument.

Remember that I wrote that its negation doesn't "necessarily" kill an argument. On a rare occasion a sufficient assumption can also be a necessary assumption, in which case the negation trick would aptly test its applicability.

bp shinners
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Re: Can a necessary assumption correct answer attack premises?

Postby bp shinners » Wed Oct 23, 2013 4:55 pm

Nope - you have to go after the gap in reasoning, not the facts on which that reasoning is based. It's like when that jerk in your class says, "Even if everything you said is true, you're still wrong." On the LSAT, you're that jerk.

Don't attack the premises - attack the flaw in the logic/assumption.

*This is for negated ACs - the AC itself should support the assumption.

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iamgeorgebush
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Re: Can a necessary assumption correct answer attack premises?

Postby iamgeorgebush » Wed Oct 23, 2013 8:36 pm

No.

Occasionally, there are weaken questions that attack the premises, but even this is very very very rare (and in the case of a premise weakener, the question would not ask you what would weaken the reasoning of the argument; it'd ask what would cast doubt on the information supporting the conclusion, or something along those lines). For pretty much all assumption questions (sufficient, necessary, strengthen, weaker, flaw), the credited response is going to address some sort of gap between the premises and conclusion or between premises and sub-conclusion.

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Re: Can a necessary assumption correct answer attack premises?

Postby bp shinners » Fri Oct 25, 2013 5:40 pm

iamgeorgebush wrote:Occasionally, there are weaken questions that attack the premises, but even this is very very very rare (and in the case of a premise weakener, the question would not ask you what would weaken the reasoning of the argument; it'd ask what would cast doubt on the information supporting the conclusion, or something along those lines).


I disagree with this. Usually, when people say that a premise is being attacked, what's actually happening is that the premise states someone believed something to be true (or something similar), and the weaken answer is that they were wrong. That's not attacking the premise - the person still believed the statement to be true - you're just pointing out the perception vs. reality fallacy.

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iamgeorgebush
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Re: Can a necessary assumption correct answer attack premises?

Postby iamgeorgebush » Fri Oct 25, 2013 7:32 pm

bp shinners wrote:
iamgeorgebush wrote:Occasionally, there are weaken questions that attack the premises, but even this is very very very rare (and in the case of a premise weakener, the question would not ask you what would weaken the reasoning of the argument; it'd ask what would cast doubt on the information supporting the conclusion, or something along those lines).


I disagree with this. Usually, when people say that a premise is being attacked, what's actually happening is that the premise states someone believed something to be true (or something similar), and the weaken answer is that they were wrong. That's not attacking the premise - the person still believed the statement to be true - you're just pointing out the perception vs. reality fallacy.

Hmm, that might be so. There's one question I'm thinking about that doesn't quite fit that mold, though.

I can't remember the exact question I'm thinking of, but it was on a post-2007 LSAT, around #7 or so (end of the second page of the LR section). If I remember correctly, one of the premises was a conclusion derived from a scientific study (not the results of the study, but a conclusion drawn from those results), the question asked something like "which of the following, if true, would cast doubt on the information supporting the conclusion?" and the credited response cast doubt on the methodology of the study. It didn't seem like a standard weakener question to me.

Also, an an aside and not that the Manhattan LR Guide is the Gospel, but I do recall the Manhattan book mentioning that once in a blue moon, a weaken question will try to weaken a premise.

izzy895
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Re: Can a necessary assumption correct answer attack premises?

Postby izzy895 » Fri Oct 25, 2013 8:26 pm

The points you've guys brought up make total sense. I also just finished up the necessary assumption drill packet so I've spent time practicing on seeing gaps and what not. But I am with georgebush on there being one question where the answer did kind of weaken the premise. I actually could of sworn I remembered reading that in a manhattan lsat forum answer as well. It migh of been a weaken question though so i apologize if it was. I'm on my through the pt's anyway so if it comes up or if anyone else finds it I'd appreciate it!

bp shinners
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Re: Can a necessary assumption correct answer attack premises?

Postby bp shinners » Thu Oct 31, 2013 2:07 pm

iamgeorgebush wrote:
bp shinners wrote:
iamgeorgebush wrote:Occasionally, there are weaken questions that attack the premises, but even this is very very very rare (and in the case of a premise weakener, the question would not ask you what would weaken the reasoning of the argument; it'd ask what would cast doubt on the information supporting the conclusion, or something along those lines).


I disagree with this. Usually, when people say that a premise is being attacked, what's actually happening is that the premise states someone believed something to be true (or something similar), and the weaken answer is that they were wrong. That's not attacking the premise - the person still believed the statement to be true - you're just pointing out the perception vs. reality fallacy.

Hmm, that might be so. There's one question I'm thinking about that doesn't quite fit that mold, though.

I can't remember the exact question I'm thinking of, but it was on a post-2007 LSAT, around #7 or so (end of the second page of the LR section). If I remember correctly, one of the premises was a conclusion derived from a scientific study (not the results of the study, but a conclusion drawn from those results), the question asked something like "which of the following, if true, would cast doubt on the information supporting the conclusion?" and the credited response cast doubt on the methodology of the study. It didn't seem like a standard weakener question to me.

Also, an an aside and not that the Manhattan LR Guide is the Gospel, but I do recall the Manhattan book mentioning that once in a blue moon, a weaken question will try to weaken a premise.


If it goes after the methodology, that isn't attacking a premise - the study still said what it said, and the author tried to conclude something from it. You're just pointing out that the study was flawed. Now if a premise said, "An unassailably perfect study proved that...", then saying there was an error in methodology would be going after a premise. I've never seen that, though.

And if someone could check for a cite in the Manhattan guide, that would be cool. I'd be more than willing to admit I'm wrong with a counterexample; I just haven't seen one where I wouldn't classify the answer as attacking an assumption instead of attacking a premise. Every time someone has brought that up to me, the answer choice has allowed the premise to still be true.




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