LSAT Explanation PT 42, S4, Q14: Over 90 percent of the human

LSAT Question Stem

Which one of the following most accurately describes a flaw in the argument? 

Logical Reasoning Question Type

This is a Flaw question. 

Correct Answer

The correct answer to this question is E. 

LSAT Question Complete Explanation

First, let's analyze the argument in the passage. The passage states that over 90 percent of the human brain serves no purpose, as evidenced by many people with significant brain damage showing no discernible adverse effects. The conclusion is that once humans begin to tap into this tremendous source of creativity and innovation, many problems that today seem insurmountable will be within our ability to solve. The premise is the statement about the human brain serving no purpose, and the conclusion is the statement about solving problems.

An "Evaluate" question for this argument could be: "Is there evidence to support that the currently unused parts of the brain are a potential source of tremendous creativity and innovation?"

Now, let's discuss the answer choices for this Flaw question:

a) The argument presumes, without providing justification, that the effects of brain damage are always easily detectable.

- This answer choice is incorrect because the argument doesn't assume that the effects of brain damage are always easily detectable. It only says that many people with significant brain damage show no discernible adverse effects.

b) The argument presumes, without providing justification, that the only reason that any problem remains unsolved is a lack of creativity and innovation.

- This answer choice is incorrect because the argument doesn't claim that the only reason problems remain unsolved is due to a lack of creativity and innovation. The argument suggests that tapping into the unused parts of the brain could help solve problems, but it doesn't say it's the only reason.

c) The argument infers that certain parts of the brain do nothing merely on the basis of the assertion that we do not know what they do.

- This answer choice is incorrect because the argument doesn't infer that certain parts of the brain do nothing based on the assertion that we don't know what they do. Instead, it bases this assertion on the fact that many people with significant brain damage show no discernible adverse effects.

d) The argument infers that problems will be solved merely on the basis of the claim that they will be within our ability to solve.

- This answer choice is incorrect because the argument doesn't infer that problems will be solved, only that they will be within our ability to solve. There is a difference between actually solving problems and having the ability to solve them.

e) The argument presumes, without providing justification, that the currently unused parts of the brain are a potential source of tremendous creativity and innovation.

- This is the correct answer. The argument assumes that tapping into the unused parts of the brain will lead to creativity and innovation without providing any evidence or justification for this assumption.

In conclusion, the correct answer to this Flaw question is answer choice E, as it accurately describes a flaw in the argument by pointing out the unsupported assumption that the currently unused parts of the brain are a potential source of tremendous creativity and innovation.