We should accept the proposal to demolish the old train station, because the local historical society, which vehement...

tainadiaz on May 30, 2019

Flawed parallel reasoning

After watching the video explanation I'm still having trouble with understanding how one would even determine what the flaw is in both the passage as well as in the answers.

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Victoria on May 30, 2019

Hi @tainadiaz,

Finding flaws in reasoning will get easier the more you practice. As you work your way through questions, you will start to recognize some of the common flaws in reasoning and find it easier to point them out. It is also helpful to do some additional reading on common errors in reasoning to develop a better understanding of what the LSAT may throw at you. For now, let's go through this question together.

The passage argues that the proposal to demolish the old train station should be accepted.

The evidence used to support this conclusion is that the local historical society opposes the demolition and the local historical society is dominated by people with "no commitment to long-term economic well-being." The passage also states that preserving old buildings impedes new development, negatively impacting economic health.

In making this argument, the author of the passage is trying to get us to believe that we should accept the proposal to demolish the old train station because keeping it impedes development that is crucial for economic health and the local historical society, who are largely not committed to long-term economic well-being, oppose this proposal.

The major flaw with this argument is that the author has based their conclusion on the fact that the proposal is supported by the local historical society. The author claims that because the society is largely composed of members who are not committed to long-term economic well-being, this must be their motive for opposing the proposal. In doing so, the author fails to recognize that there may be other reasons why the local historical society opposes the proposal; for example, historical significance of the building.

More generally, the flaw in this argument is that the author draws their conclusion based solely on the fact that the advice comes from a group that they believe to have ulterior motives.

Now, let's go through the answer choices.

A argues that our country should safeguard all works of art that it deems to have national cultural significance even if this significance is not recognized by others.

B argues that documents that are important for local heritage should be preserved and archived for future generations because, if they are not, the integrity of the historical record will be damaged.

C argues that you should not cut your hair more than once a month because beauticians recommend that customers have their hair cut twice a month and they do so as a way of generating more business.

D argues that the committee should endorse the plan to postpone construction because many potentially affected residents are opposed to the plan and the committee is obligated to avoid alienating those residents.

E argues that you should not borrow money unless it is absolutely necessary because interest accumulates over time and can turn small debts into large ones.

As we can see, C directly mirrors the flaw in reasoning exhibited in the passage. By arguing that you should not have your hair cut more than once a month because beauticians say you should have your hair cut twice a month and they do so as a way of generating more business for themselves ignores the possibility that having your hair cut twice a month may also be good for your hair. In this way, the author makes their conclusion based solely on the fact that the advice comes from beauticians who they believe have ulterior motives, i.e. generating more business for themselves.

Hope this is helpful!

Keep up the practice and the skills should come with time!

Please don't hesitate to let us know if you have any further questions.