Since anyone who supports the new tax plan has no chance of being elected, and anyone who truly understands economics...
iameunkyoung@gmail.comMarch 11, 2020
Similar question stimulus..
I was reading the common fallacies part given in the Errors in Reasoning section and encountered this eg question that is similar as this question. And I seem to have a hard time seeing the exceptional groups (= what the argument ignores in making conclusions as this one). And the question goes
Political theorist: The chief foundations of all governments are the legal system and the police force; and as there cannot be a good legal system where the police are not well paid, it follows that where the police are well paid there will be a good legal system.
The reasoning in the argument is not sound because it fails establish that
A) many governments with bad legal systems have poorly paid police forces
B) bad governments with good legal systems must have poorly paid police forces
C) a well-paid police force cannot be effective without a good legal system
D) a well-paid police is sufficient to guarantee a good legal system some bad governments have good legal system
E) some bad governments have good legal systems
My questions are:
1. What is the correct answer?
2. Does this diagram work for this question?
Premise 1. CFofG -> LS and PF
Premise 2. not PWP -> not GLS (GLS -> PWP)
----------------------------------------------
Conclusion: PWP -> GLS
3. if this is correct, I think the error was the improper negation.
But choosing a correct answer is something beyond identifying error type, since I need to know which group in the choices can be used as an example that doesn't belong in his argument.
Would it make sense that I need to find
PWP -> not GLS
GLS -> not PWP ?
this seems to not belong in any of his S/N conditions..
Thanks in advance!
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First, let's talk about the question that you commented on. "What does the argument ignore when drawing the conclusion?" It might be easier for you to recognize the right answer if you think of things in terms of sufficient and necessary conditions. Focus on how the premises lead to the conclusion. I'll explain.
P: Anyone who supports the tax plan (STP) has no chance of being elected (not E). STP - -> not E E - -> not STP
P: Anyone who truly understands economics (TUE) would not support the tax plan (not STP). TUE - -> not STP
C: Only someone who truly understands economics would have any chance of being elected. E - -> TUE
We know that not supporting the tax plan is necessary for election. But the author has concluded that true understanding of economics is also necessary for election. Where is this coming from? Take a look at the second premise. This is what the author has misunderstood. He thinks that true understanding is necessary for not supporting the tax plan. But that is not true. There may be other ways not to support the tax plan. This is what is being ignored, and it is best expressed by answer choice D. There could be people who reject the tax plan without understanding economics.
Now, to the question that you transcribed. I wouldn't necessarily have diagrammed that first sentence, because there is no conditional reasoning. There are no sufficient and necessary conditions, so I see it more as background information.
The conclusion seems to be based entirely on your second premise, which you did diagram correctly. GLS - -> PWP not PWP - -> not GLS
However, as you already know, the conclusion the author drew was this: PWP - -> GLS
Improper negation is one way to put it, but I would prefer to call it a reversal of sufficient and necessary conditions. This is the exact same mistake from the question above (TUE - -> not STP vs. not STP - -> TUE), and it is a very common one on the LSAT. It will often appear among answer choices as, "The author has mistaken a sufficient condition for a necessary one."
This is best expressed by answer choice D. When an author assumes that something is sufficient/necessary, but that isn't supported by the premises, then he has failed to establish that assumption.
