Even though this question is old, it has several lessons built into it. I was able to parse this question out mainly because of the lessons on 7Sage. The first lesson I see with this question is the importance of being attuned to the grammar of the LSAT. The stimulus begins with “since.” This should reference back to the core curriculum grammar lessons: “since” generally introduces something that we will be using to build towards a conclusion. In other words, we are hurled by the first word of this argument into a premise. We also have an additional premise that is introduced by the word “and.” We then have a comma and the conclusion is given to us in conditional language. I sometimes feel on LR that what I am given in a stimulus is like joining a conversation mid-talk and I am expected to piece together the information into the way the authors want us to. This is a perfect example of that phenomena in my estimation.
The second lesson in this question is the heavy use of conditional language. You have to know your conditional indicators in order to map this question correctly. What we end up getting when we map this question is:
P 1:If you support the new tax plan——>no chance of being elected.
P 2:If you truly understand economics——>Not support the new plan.
C:If you have a chance of being elected——>truly understand economics
The third lesson from this question is the idea that questions are often related in the task they set out for us, a deep understanding of this sits at the bottom of the case for reading the stimulus before the question stem: if you can tell what is wrong from the stimulus this thinking goes, the question stem shouldn't have to be read first (I am not a proponent of this view.) When I lined those conditionals up, out of habit I wanted to find the sufficient assumption. Well it turns out that if we look at this question through a sufficient assumption lens, we can actually garner quite a bit. Lets take the contrapositive of that first statement:
P 1: If you have a chance of being elected——>Not support new tax plan
P 2:If you truly understand economics——>Not support the new plan.
C:If you have a chance of being elected——>truly understand economics
So insofar as the premises supporting the conclusion this isn’t a valid argument. But why? Above there is simply no way to get from the premises to the conclusion. The forth lesson dawned on me when I was BR’ing this question: This is where the flaw really is: as currently stated, the premises do not support the conclusion. Familiar terms are used in the premises and conclusion as a way to distract us, but the conclusion might as well be something about football or motorcycle maintenance. There is simply no support for the given conclusion from the given premises. The relationships between the elements do not support the given conclusion.
This is when we take a look at the fifth lesson embedded in this question and that is to take a close look at the question stem. This isn’t actually asking what the flaw is in the way we are all used to. Instead, this question is asking us for something that the argument ignores the possibility of. More specifically, that the argument ignores the possibility that “some people who _____” The fifth lesson here is how to deny a conditional relationship. So if I were to give you the conditional relationship: All cats are mammals, you would deny that by saying “some things that are cats and not mammals.” The existence of a thing that is both a cat and not a mammal is enough to deny the sufficiency of something being a cat triggering the necessary condition of being a mammal. With this knowledge in mind lets take a closer look at what we are given in the stimulus.
chance of elected———>Not support new tax plan
+
Understands economics——>Not support new tax plan
Conclusion:
Chance elected——>Truly understands economics
How could we make this valid? We could say that Not support new tax plan——>Understands economics!
99 times out of 100, if we have gotten this far and we are stuck, it was actually our translation of the logic where we have gone wrong. Meaning if this was a sufficient assumption question, I would bet that I had translated something wrong. But, we didn’t. The only other possibility is something very peculiar: it appears that our author has given us: Understands economics———>Not support new tax plan, but has interpreted this statement in logic to mean: Not support new tax plan———>Understand economics! If we (wrongly) interpret the second condition as Not support new tax plan———>Understand economics, we have a simple A——>B——>C argument.
This is an incredibly difficult step to take. I am open for correction here, but the idea that we are given a conditional statement, that we translate correctly, but have to take a leap in judgement to conclude that the author might have interpreted that conditional statement wrong is hard enough. Finding where the author’s translation went wrong and then negating that translation to point out the flaw makes this, for my money, the hardest flaw question of all time. The author's assumption here is actually a mistranslation of the logic to: Not support new tax plan———>Understand economics The denial of this is (D)
I look forward to a correspondence with members of this community about this question. Has anyone come across something like this elsewhere? Would it behove us to classify this flaw under the umbrella of sufficient/necessary flaws more generally? Thank you!
David
**Admin note: edited title**
Comments
So I like what you have written above and I think essentially how you and I did this question is pretty similar to get to the correct answer except I took different steps.
Since were are just corroborating, I thought I would write down how I got to my answer. : )
step #1: I quickly wrote down my premises and conclusion
P1: S --->/E ("S" is support the new tax plan and "E" is for elected.)
P2: U-->/S ("U" stands for understand economics)
C: E-->U
Step #2: I just quickly remembered what my task is here, the author is going wrong somewhere here and I need to point out what he is forgetting. So lets work the authors logic, not mine.
Our authors conclusion is starting from "E", as "E" is in sufficient condition; so lets flip our first premise to reflect that:
P1: E---->/S
Now lets connect our second premise to this flipped premise#1, so we can see better what the author of this statement is doing.
So if we connect our second P2 to our flipped P1, we get:
E-->/S
U-->/S
but the author is concluding E---->U (here I asked, well "what argument form will allow me to conclude E-->U?)
So if I have E--->/S --> U, I can agree with the author's conclusion that E--->UE. So now I see what the author is doing, he is doing the fallacy of sufficient and neccessary reversal. But since this answer requires us to point out what exactly he should have considered, we need to keep working on what exactly the author should have considered but is not.
So the author is treating U-->/S as the same as /S-->U.
Since the author is using "/S" in sufficient indicator, lets compare it to what he should have concluded vs what he is actually concluding. So right now we have U-->/S. If we want to put /S as sufficient condition, we will have to use our inherent inferences to do that. The only thing we can conclude by putting "/S" in sufficient is "/S<---some-->/UE". This is because "all" implies "some". But the author is taking a "some" statement (/S<--some-->U) and using it like its an all statement "/S------>/U". So the author is basically forgetting that "some" does not mean "all" and that there are other possibilities where /s could also lead to /U. We just don't know for sure, but its a possibility. And that's what answer choice "D" is doing. Its saying hey, it was a some statement and you are treating like the other possibilities that could also lead from /S in sufficient condition like "/U" do not exist.
I like to see Flaw questions that ask me to find out what exactly the author of the stimulus is actually forgetting as similar to a situation if I was helping someone in their LSAT prep. If I was helping someone on LSAT, I felt like I wouldn't have just stopped at saying, "hey, you are doing a mistaken reversal flaw". I would have said "hey, look I can see what you are doing, you are flipping a conditional statement but here let me help you see why you cannot do that." In doing this not only would I have to know what it is we can conclude from our two premises, but I would have to also understand from the point of view of that person where exactly he/she is missing in understanding of logic. And then point out that mistake and tell him hey, you havn't considered this point.