Logical reasoning PrepTest 158 · Section 4 · Question 7

This doesn't strengthen the argument. It isn't necessary for the argument, either.

It doesn't strengthen the argument because it doesn't tell us when the Sumerians created literature. It just tells us that the Egyptians may have created a lot of literature. But if all this literature came after the Sumerian literature, we can't convincingly argue that the Egyptian tablets challenge historians' belief that the Sumerians were the first to create literature.

This also isn't necessary to the argument because we only need one example of Egyptian literature to show that the Egyptians may have created literature before the Sumerians. We don't need a lot of examples, so this answer choice isn't needed to draw the newspaper's conclusion.

Finally, this is the argument we'd make if we used the backup plan:

"We found some Egyptian clay tablets from 3300-3200 B.C. Some clay tablets appear to have literary writing. But, it's not true that most of the recently discovered tablets that have not yet been translated contain literary writing. So, the Sumerians may have been the first to create literature."

This doesn't make a lot of sense. There's still a big gap between the premises — which are all about the Egyptian tablets — and the conclusion about Sumerians.

No matter which approach we use, we can confidently cross off (A).

This doesn't strengthen the argument. It isn't necessary for the argument, either.

It doesn't strengthen the argument because it doesn't tell us when the Sumerians created literature. It doesn't even tell us that the Egyptians created literature. It just tells a civilization that keeps tax records keeps other kinds of written records, too. But "other kinds of written records" doesn't mean that the country makes literature. 

This also isn't necessary to the argument because the newspaper article only needs to establish that Egyptians and Sumerians created literature. We don't need to know about "every civilization that has kept tax records." This provides information about far more civilizations than just the Egyptian and Sumerian civilization, so this answer choice isn't needed to draw the newspaper's conclusion.

Finally, this is the argument we'd make if we used the backup plan:

"We found some Egyptian clay tablets from 3300-3200 B.C. Some clay tablets appear to have literary writing. But, it's not true that every civilization that has kept tax records has also kept other written records. So, the Sumerians may have been the first to create literature."

This doesn't make a lot of sense. There's still a big gap between the premises — which about Egyptian tablets and civilizations that keep tax records — and the conclusion about Sumerian literature.

No matter which approach we use, we can confidently cross off (B).

Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen with a Necessary Premise

Passage Summary:
We found some Egyptian clay tablets that are from 3300-3200 B.C. Some clay tablets appear to have literary writing. So, Sumerians may not have been the first to create literature.

Strategy Overview:

1. Argument or facts? Always argument, so identify premises and conclusions of argument
2. Anticipate why the premises are not enough to show that the conclusion is true
3. Use anticipations to select the answer choice that:
1. Strengthens the conclusion of the argument, and
2. Is necessary for the conclusion of the argument
1. Can use "negation test" to double-check: if this answer choice isn't true, does the conclusion become untrue as well? If so, it's necessary for the conclusion of the argument, and it is the correct answer

Answer Anticipation:
On Strengthen with a Necessary Premise questions, it's our job to find the answer choice that (a) strengthens the argument's conclusion and (b) must be true to draw the conclusion. At first, finding an answer that matches both criteria is very challenging for many test-takers.

But with much practice, experienced LSATers develop a reliable strategy. All Strengthen with a Necessary Premise questions feature flawed arguments, and it's much easier to find the correct answer after identifying why the argument is flawed. After all, fixing that flaw will strengthen the argument, and showing that the flaw is fixable is necessary to draw the conclusion.

For most Strengthen with a Necessary Premise questions, the flaw involves introducing a new, important idea in the conclusion, creating a gap between the premises and conclusion. This argument's conclusion is basically all new information. The idea that historians believe that the Sumerians were the first to create literature is all new information. The premises just establish that the newly discovered Egyptian clay tablets are from 3300-3200 B.C. and may contain literature. There's a big gap between these premises and the conclusion. The premises don't tell us when the Sumerians created literature, so we can't say these tablets show that Egyptians created literature before the Sumerians. The correct answer will probably bridge this gap by establishing that Sumerian literature is not older than these tablets.

Finally, many test-takers find the backup plan helpful on these questions. To resort to the backup plan, we'll re-read the premises. Then, we'll say, "But, it's not true that," and re-read the answer choice. (We can just say "But" and then read the negated form of the answer choice.) Finally, we'll say, "So, it may not be true that ..." and re-read this argument's conclusion. (We can just say "So" and then read the negated form of the conclusion.) If that argument makes sense, we'll know the answer choice expresses a necessary assumption. If the argument doesn't make much sense, then we can cross that answer choice off. Here's a simplified template we can use for this backup plan (note that we simplified the premises and conclusion and included the

negated form of the conclusion):

"We found some Egyptian clay tablets from 3300-3200 B.C.

"Some clay tablets appear to have literary writing.

"But, it's not true that [answer choice].

"So, Sumerians may have been the first to create literature."

Answer Choice Explanation:
As we anticipated, this answer choice strengthens the argument by telling us that Sumerians didn't create literature older than these Egyptian tablets. These Egyptian tablets were created sometime between 3300 and 3200 B.C. So, this answer choice establishes that historians don't believe that Sumerian literature is older than the Egyptian tablets. This makes us more confident that the Sumerians may not have been the first to create literature.

We also need to know this to draw the conclusion that the Sumerians may not have been the first to create literature. If the Sumerian literature was older than the Egyptian tablets, then we could not confidently claim that the Sumerians may not have been the first to create literature.

We can also evaluate this answer choice using the backup plan. Here's the argument we'd make if we used the backup plan (note that we simplified the answer choice to make this easier to read):

"We found some Egyptian clay tablets from 3300-3200 B.C. Some clay tablets appear to have literary writing. But, the Sumerians created literature before 3300 B.C. So, the Sumerians may have been the first to create literature."

This makes sense. Yes, we found old Egyptian clay tablets that may contain literature, but we know that Sumerians created literature older than these tablets. So, the Sumerians were probably the first to create literature, at least as far as we know.

Therefore, no matter which approach we used, we can be confident that (C) is the correct answer.

Key Takeaways:

Experienced LSATers simplify Strengthen with a Necessary Premise question by focusing on the gap between the premise and the new term in the conclusion. On this particular question, only one answer choice addressed that gap at all.

This doesn't strengthen the argument. It isn't necessary for the argument, either.

It doesn't strengthen the argument because it doesn't tell us when the Sumerians created literature. In fact, it weakens the argument by calling its evidence into question. If we don't think these tablets are genuine, then we don't have good evidence to challenge the historians' belief that Sumerians were the first to create literature. Further, anything that weakens the argument won't be necessary to the argument, either.

Additionally, this is the argument we'd make if we used the backup plan:

"We found some Egyptian clay tablets from 3300-3200 B.C. Some clay tablets appear to have literary writing. But, it's not true that some historians are skeptical about the authenticity of the recently discovered tablets. So, the Sumerians may have been the first to create literature."

This doesn't make a lot of sense. There's still a big gap between the premises — which about Egyptian tablets — and the conclusion about Sumerian literature. Plus, what follows the "But" seems consistent with the premises that came before it, making the paragraph sound awkward.

No matter which approach we used, we can confidently cross off (D).

This answer choice strengthens the argument. If the Sumerian civilization rose between 3300 and 3200 B.C., then it almost certainly didn't create literature that's older than the supposed literary writing on the Egyptian tablets. For this reason, some test-takers believe (E) is the correct answer.

However, this answer choice isn't needed to draw the newspaper's conclusion. Even if the Sumerian civilization arose before 3300 B.C., it still could have created literature after the Egyptians. Perhaps the Sumerian civilization arose before 3400 B.C. but created literature in 3100 B.C. In that case, we could still conclude that the Sumerians may not have been the first to create literature.

Finally, this is the argument we'd make if we used the backup plan:

"We found some Egyptian clay tablets from 3300-3200 B.C. Some clay tablets appear to have literary writing. But, it's not true that the Sumerian civilization arose sometime between 3300 and 3200 B.C. So, the Sumerians may have been the first to create literature."

This doesn't sound like a valid argument. There's still a gap between the last premise — which tells us when the Sumerian civilization was formed — and the conclusion — which tells us when the Sumerian civilization created literature. The Sumerian civilization could arose before 3300 B.C. and created literature older than the literary writing found on the Egyptian tablets.

No matter which approach we use, we can confidently cross off (E).