Student: The publications of Professor Vallejo on the origins of glass

Question

Student: The publications of Professor Vallejo on the origins of glassblowing have reopened the debate among historians over whether glassblowing originated in Egypt or elsewhere. If Professor Vallejo is correct, there is insufficient evidence for claiming, as most historians have done for many years, that glassblowing began in Egypt. So, despite the fact that the traditional view is still maintained by the majority of historians, if Professor Vallejo is correct, we must conclude that glassblowing originated elsewhere.

Which one of the following is an error in the student’s reasoning?

(A) It draws a conclusion that conflicts with the majority opinion of experts.
(B) It presupposes the truth of Professor Vallejo’s claims.
(C) It fails to provide criteria for determining adequate historical evidence.
(D) It mistakes the majority view for the traditional view.
(E) It confuses inadequate evidence for truth with evidence for falsity.

arvind910619 · Answer

Found this this question to be very challenging. 
Here is my take.

A is out as there is no conflict, but there is negation of the majority's view.
B It does not presupposes. Rather the argument takes Professor Vallejo’s claims to be hypothetically true.
C Criteria is not discussed. It also not required. This option is out of scope.
D No this is not true.
E is correct. If Professor Vallejo’s claims are true then the majority's view is false is not correct. There might be insufficient evidence does mean that the view majority view is false. Evidence may buried in some sites which are yet to be unearthed.

JohnWidestone · Answer

A: He does, but this is not an error in the reasoning. 
B: He does not presuppose it as the truth as he stats that: " If Professor Vallejo is correct, ..."
C: This is out of scope.
D: In this case the majority view is the traditional view, but this does not influence the reasoning.
E: He states that:" there is insufficient evidence,...". Just because the evidence is insufficient, if Professor Vallejo is right, does not mean it is false, thus the conclusion that glassblowing must have originated somewhere else can't be drawn.

akela · Answer

ManhattanPrep explanation

Flaw answers can be worded quite strangely - and you'll want to understand every flaw answer choice you meet (though during a test, if you know it's wrong, no need to figure it out deeply right there - look back at it later when you're reviewing). The wording in (E) is not unusual, but you'll probably not see it on your exam!

Let's take a look at this question:

The conclusion is that if Professor Vallejo is correct, than glassblowing didn't originate in Egypt.

Why? Because if the Professor is correct, there isn't enough evidence to conclude that glassblowing began in Egypt.

Hmm, that's fishy. That's like saying this: There isn't enough evidence to say Joe stole the car, so he definitely didn't.

Clearly, the absence of evidence is not proof of anything. (E) states this, albeit in a strange fashion. Let's decode it:

It confuses inadequate evidence for truth   with evidence for falsity  . Tricky!

As for the wrong answers:

(A) is tempting, since Professor Vallejo does seem to go against the opinion of most historians. However, that's not a problem! You're allowed to disagree with the majority!

(B) is not true - the student is not assuming the professor is correct. The student states "if Professor Vallejo is correct.." which is far from assuming that the the Professor is correct!

(C) is tempting because it's complex-sounding. However, why would the student need to set up criteria for deciding if something is adequate historical evidence? The student is simply saying that if the professor is correct, we can conclude something. Perhaps this answer would be correct if the argument were about saying whether a piece of evidence means something, not, as we have here, whether an opinion means something.

(D) is perhaps tempting since the argument refers to the "traditional view" and to what the "majority of historians" believe. However, the argument doesn't confuse those two. The student states that the majority hold the traditional view - which suggests they could be different.

VerbalBot · Answer

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Student: The publications of Professor Vallejo on the origins of glass

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Student: The publications of Professor Vallejo on the origins of glass

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