#21- The new agriculture bill will almost surely fail to

[Ron Gore]

You're welcome!

[Frank]

Hey,

I am kinda curious about this question too. I answered A but it took me a while and going back over it again I thought that the question was actually a conditional argument.

The conclusion is ~P (will not pass) and the premise is ~S (no support), so isn't the main gap in the argument that ~S is sufficient to show ~P? Answer choice A gives you this missing link (~S --> ~P) but I when I was going over the answers it seemed like E could be right as well since it is the contrapositive (P--->S). Is this the right way to be attacking this question and if so how do distinguish between A and E?

Thanks for your help

Frank

[Adam Tyson]

Good question, Frank - Answer E does look like the contrapositive, and if this was truly conditional reasoning then it would be a good answer.

What we have here, though, is not truly conditional reasoning. Rather, it's what we typically call Pure Logic. The introduction of words like "some" and "most" into what otherwise look like conditional statements turns them into this other type of reasoning that has slightly different rules. Some folks use Venn diagrams - a series of interlocking circles - to show how pure logic works, but those are hard to draw here and they also aren't really needed.

Try thinking about some numbers as we analyze answers A and E here. Let's say there are 100 bills that have been considered by the legislature. Most of them - let's say 75 - had the support of at least one major party leader, and most of those - let's say 60 - were passed into law. Now imagine that the other 25 that were considered were all passed into law, even though they had no leader of a major party supporting them. That would fit the facts presented in Answer E, because most of the bills that passed (60 out of 85) had that support. That situation wouldn't strengthen the claim that the agricultural bill, which has no such support, is unlikely to pass. In fact it would weaken the argument, because 100% of the bills without that support passed. Statistically, at least, it looks like you're better off without the support than with it.

The info in Answer A means the relative numbers (comparing the ones with support to the ones without) don't matter - most of the bills like this ag bill, the bills without support, don't pass. Putting aside the time shift error that Ron rightly pointed out, that does suggest that it is more likely than not that the ag bill will not pass.

We don't see nearly as much pure logic on this test as we do conditional reasoning, but when you do see what appears to be conditional reasoning modified by words like some and most, the contrapositive becomes less helpful, and it's better to think about numerical relationships instead.

I hope that cleared it up for you! Good luck in your continued studies.

[Frank]

Thanks Adam, that's a helpful analysis of the question!

[LSAT2018]

I always thought for formal logic, statements with 'some' have contrapositives while statements with 'most' cannot have contrapositives. Is this why Answers (D) and (E) are wrong?

[Adam Tyson]

When looking at Formal Logic, LSAT2018, a "some" statement flows both ways - if some pizzas have anchovies, then some anchovies are on pizzas. I don't usually refer to that as a contrapositive, because it isn't about negating anything or anything being necessary or sufficient. We sometimes refer to that as the "some train", and it runs in both directions.

A "most" statement DOES have an inference that flows in the opposite direction, but it is only a "some" statement that comes back. If MOST pizzas have cheese, then SOME cheese is on pizzas. I cannot say that most cheese is on pizzas because "most" only goes one way, but I can say that some cheese is on pizzas because "most" is definitely more than zero and thus includes the concept of "some".

Answer D isn't bad because of a contrapositive problem. It's bad because the issue isn't unanimous support among the leaders but rather a unanimous LACK of support. The opposite of that would be some support, not unanimous support.

Answer E certainly looks a lot like a contrapositive! If the claim we need is "if you don't have support, you will probably not pass", and we wanted to create something like a contrapositive of that claim, we would say "if you are probably going to pass, then you have some support." That's a little bit off from "if you passed, you probably had support" because "passed" and "probably passed" are not the same concept.

I hope that helps some! I know how confusing these claims can be! That's why I love to throw numbers at them, as I did earlier in this thread. They help me see more clearly sometimes than the more abstract language of quasi-conditionality.

[nadianyc]

Hi!
This is my first time using this board, and I have been having trouble working through a specific Strengthen question:

"The new agriculture bill will almost surely fail to pass. The leaders of all major parties have stated that they oppose it.
Which one of the following, if true, adds the most support for the prediction that the agriculture bill will fail to pass?"

The conditional statement is: "If Leaders of all major parties DO NOT support the bill ==> Bill will not pass," leading to answer choice A.
However, choice E (which I originally chose) is looking for a contrapositive that states: "Bill DOES pass ==> Leaders of ALL major parties DO support the bill."

My confusion stems from the negation. I thought that I would have to switch the "ALL" to "none" or "some" in the contrapositive, because the conditional statement states "all" as well. Should I always leave "all" alone, or are there some cases in which "all" is negated as well?

Thanks so much!

[Stephanie Oswalt]

Hi nadianyc,

Thanks for the post, and welcome to the forum! We actually organize the forum by test section, test #, question #, etc., in order to make it easier for students to use. I have moved your post to the thread discussing this question. Please review the above discussions, and let us know if that helps or if you still have any additional questions. Thanks!

[nadianyc]

Hi Stephanie!

Thank you so much for the introduction and the explanation, I will be sure to comment on the correct threads from here on out.
This thread offered so many helpful components to this question, and I have learned a lot while reading through the various comments and questions, especially Adam's comment from 2018 explaining the answer choices in further detail.

Thanks again!

[slynnnnn]

Hi PowerScore Team,

I narrowed down to (A) and (E) during the practice exam. Upon reading the previous threads, I am confused about the negation of the conclusion.

To me, it works like this...
Conclusion: all major party leaders oppose → bill fail
Contrapositive: bill NOT fail → NOT all major party leaders oppose → at least one will support (which is exactly what E says)

In a previous thread, it says that contrapositive should be "Leaders of ALL major parties DO support the bill". Can you please help me to clarify my confusion?

However, upon second thought, it came to me that were I right on the negation, answer (E) would simply have been a restatement to the conclusion, and would not offer any support for the prediction. On the other hand, answer (A) offers additional piece of information, making it a superior answer than (E). Would that be a correct thinking process?

Thanks,
Lynn