June 1995 LSAT Section 2 Question 23

No computer will ever be able to do everything that some human minds can do, for there are some problems that cannot ...

Branden on January 12, 2021

All Answer Choices

I am having trouble understanding how any of them are wrong and how B is correct. I crossed out B, C, and D, and chose E and still don't understand why B is correct and why E and A are wrong.

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shunhe on January 13, 2021

Hi @Branden,

Thanks for the question! So this is a strengthen with necessary premise question. We can use the negation test. You should’ve diagrammed the stimulus:

P: some problems can’t be solved by following any set of mechanically applicable rules
P: computer solve problem —> follow set of mechanically applicable rules
C: Computer —> ~Do everything a human mind can

(B) says the argument assumes that at least one problem not solvable by following any set of mechanically applicable rules (MAR) is solvable by at least one human mind. So there’s a human out there that can solve a problem where you can’t follow the MAR. Well, the argument does need to assume the truth of this statement! Assume it’s false. Then humans can’t solve non-MAR problems. But computers could theoretically solve all MAR problems. So if humans can only solve MAR problems too, then computers might be able to do everything humans can do. If (B) is false, the argument falls apart, and so it’s the necessary assumption.

(A) says at least one MAR problem isn’t solvable by humans. Well, that doesn’t matter, because we’re trying to show that humans can solve problems computers can’t, not the other way around.

(C) says that at least one problem solvable by MAR is solvable by every human. The argument doesn’t need to assume something this strong. It doesn’t need to be the case that EVERY human can solve it. We just need at least one human to be able to solve it. (C) assumes too much.

(D) says that every MAR problem is solvable by almost every human mind. Again, we need to show that humans can solve non-MAR problems.

(E) says that every problem solvable by MAR is solvable by at least one human mind. Same problem as (D).

Hope this helps! Feel free to ask any other questions that you might have.

Branden on January 14, 2021

Thank you! I understand it better now!

shunhe on January 15, 2021

Glad I was able to help!