LSAT Question Explanation
PT 105, Section 1, Question 10
Identify the FlawArgument structure
Surgery done by anyone other than a general surgeon has highly undesirable risks.
You need someone highly competent to perform surgery if you want to avoid highly undesirable risks, and general surgeons are highly competent.
Explanation
The evidence here has some conditional logic. I tells us that it's necessary to have a highly competent surgeon, or else you could have highly undesirable risks. And then it tells us that general surgeons are highly competent.
However... in the conclusion it treats being a general surgeon as necessary to avoid risks. In the evidence being a general surgeon was sufficient for being competent, the evidence never said that only general surgeons are competent. It's quite possible that there are other people who are highly competent surgeons, and thus those people may also be able to perform surgery without the highly undesirable risks.
This is a sufficient/necessary swap, here's the diagram:
E: General Surgeon → Highly competent C: Highly Competent → General Surgeon
Answer choices
This actually is considered, it's disproven by the second sentence. It's also not relevant to the conclusion because the author wasn't claiming in the conclusion that all general surgeons are competent, they were mistakenly claiming that only general surgeons are competent and no one else is.
This points out the flaw. The second sentence told us that general surgeons are competent, but nowhere in the evidence did it say that no one else could be competent.
This isn't relevant to the conclusion which was about whether or not people besides general surgeons can be competent.
This is again irrelevant to the conclusion because it doesn't relate to whether or not general surgeons are the only competent people.
Again, irrelevant. We need to stay focused on the flaw, or why the author's claim that general surgeons are the only competent doctors isn't proven. This answer choice doesn't have anything to do with the argument.