A history book written hundreds of years ago contains several inconsis

The question is "The conclusion cited does not follow UNLESS...." So this is a Disguised Assumption question. We have to find an answer choice that must be true so that the conclusion holds.

Interesting question. My take is as follows:

CONCLUSION: The author MUST have been getting information from MORE THAN ONE source
WHY?
BECAUSE his history book contains several inconsistencies.

(A), (B), and (D) are all irrelevant, and (E) somewhat STRENGTHENS the Conclusion but is not the Assumption. If we negate (E), it becomes: The author of the history book WAS NOT familiar with ALL of the available source material that was relevant to the history book. But the author MAY have been familiar with and getting information from MOST of the available source material. Negation of (E) does NOT break the Conclusion.

(C) is the required Assumption because if we negate (C), it becomes: The history book's author used SOME SOURCE that contained inconsistencies repeated in the history book. This breaks the conclusion that the author MUST have been getting information from MORE THAN ONE SOURCE. (C) excludes the possibility that the author used SOME SOURCE that contained inconsistencies ON ITS OWN, leaving the ONLY POSSIBILITY that the author got information from MULTIPLE SOURCES. (C) is correct.

I hope it helps you guys.

A history book written hundreds of years ago contains several inconsistencies. Some scholars argue that because the book contains inconsistencies, the author must have been getting information from more than one source.

The conclusion cited does not follow unless

(A) authors generally try to reconcile discrepancies between sources

(B) the inconsistencies would be apparent to the average reader of the history book at the present time

(C) the history book’s author used no source that contained inconsistencies repeated in the history book

(D) the author of the history book was aware of the kinds of inconsistencies that can arise when multiple sources are consulted

(E) the author of the history book was familiar with all of the available source material that was relevant to the history book

Its a strengthen question so the option that does that is the right answer.
Of all the options only D and E are close.

As per D author of the history book must be aware of type of inconsistencies upfront which does not make sense as in how someone would be knowing about unknowns. Even if the author is, then he/she certainly frown eyes before penning them down.
On the contrary, if the author knows about the source material that was relevant to the history book he/she would use. Since everything that seems relevant is used inconsistencies are natural to arise.

IMO Answer E.

You should look closely at this sentence in the argument to understand the author's logic: "Some scholars argue that BECAUSE THE BOOK CONTAINS INCONSISTENCIES, the author MUST HAVE BEEN GETTING INFORMATION from more than one source." (also notice the key word "MUST".) About how does consulting multiple sources introduce inconsistencies in a book, for example, the historian consults 2 books: book (A) says that event X happened BEFORE event Y whereas book (B) says that event X happened AFTER event Y, and he put all these pieces of information somewhere in his history book. But it is possible that the historian consulted only 1 book and that book contained the inconsistencies above. (C) excludes this possibility. If you negate (C), it is not necessarily true that the historian DEFINITELY consulted multiple sources (as the argument uses the word "MUST") because it is possible that he consulted only 1 source that contained inconsistencies within itself. Negation of (C) breaks down the conclusion and is therefore the required assumption.

Hello, shameekv1989. I took the question blindly, without reading anything ahead of time, and answered correctly in 1:29. I see now that analytica233 has explained the correct line of reasoning to your satisfaction. If I could boil it down to one line, it would be that if the author of the history book in question incorporated inconsistencies that had already appeared in a single source, then the argument that inconsistencies must mean multiple sources would break down, so (C) must be our answer.

If you need anything else on this one, just let me know. Thank you for drawing my attention to the question.

- Andrew

I think it's B. Because back then people wasn't familliar with the scientific approach

analytica233 :- I couldn't understand but hoping if you could elaborate.

If the author used more than one source and that none of those sources contained inconsistencies then where did the inconsistencies in the book come from? All the multiple sources are accounted for when the assumption says no source contained inconsistencies.

MentorTutoring - Hi Andrew, Could you take a moment to help me out with this question.

This is my reasoning to reject the correct answer - "If the author used more than one source and that none of those sources contained inconsistencies then where did the inconsistencies in the book come from? All the multiple sources are accounted for when the assumption says no source contained inconsistencies."

Hi shameekv1989

That the history book contains inconsistencies is a FACT. The argument CONCLUDES that "the author MUST have been getting information from MULTIPLE SOURCES". This means that the argument ATTRIBUTED the INCONSISTENCIES within the history book TO the author's ACTION of CONSULTING DIFFERENT SOURCES (each course is consistent but because he consulted MULTIPLE SOURCES, inconsistencies happened.) BUT what if the author consulted ONLY ONE SOURCE to write his book and that source contained inconsistencies WITHIN ITSELF??? In order that the conclusion "the author MUST have been getting information from MULTIPLE SOURCES" CAN be valid, we must EXCLUDE the possibility that he used ONLY ONE SOURCE but that one source contained inconsistencies ON ITS OWN. (C) tells us exactly this: (C) the history book’s author used NO source THAT CONTAINED INCONSISTENCIES REPEATED in the history book.

I hope it helps!

How do just consulting multiple sources introduce inconsistencies in a book? For this to be valid, we should know that CONSULTING MULTIPLE SOURCES IN ITSELF CAN INTRODUCE inconsistencies not the inconsistencies in the source itself.

I don't know if you get my point?

Hey, thanks for taking the time and clearing my doubts by giving an example. It kind of clears up everything. I think I just couldn't visualize the argument that way. Amazing breakdown!! +1 to you!!

Hey, thanks for taking the time and clearing my doubts by giving an example. It kind of clears up everything. I think I just couldn't visualize the argument that way. Amazing breakdown!! +1 to you!![/quote]

You're welcome, man. I had been also very confused regarding these types of questions. Just keep investigating each question until you completely understand why each answer choice is correct or incorrect and one day you will find everything makes sense. See you around!

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