Logical ReasoningDifficulty: Medium

PT142 S1 Q12 Explanation

Archaeologists are discovering

A free, expert breakdown of this official LSAT Logical Reasoning question.

TopicsSufficient Assumption

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Stimulus

Archaeologists are discovering a great deal about the Sals culture. For example, recent excavations have unearthed smelting furnaces and tools of smelted copper and bronze. There were distinct Sals words for copper and for the Sals did not smelt iron.

What this question is testing

Sufficient Assumption

Your task

Find the assumption that, if added, guarantees the conclusion follows.

Common trap

Answers that only partly bridge the gap, leaving the conclusion unproven.

Winning move

Identify the new term in the conclusion and pick the choice that links it to the evidence.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
12.

The conclusion drawn above follows logically if which one of the following

Answer choices

  1. Unrelated to Goal19% picked this

    If a culture had a distinct word for a metal, then it

    This is a rule that looks like this: xyz ----> did smelt that metal But to prove the conclusion we're trying to prove, we need a rule that looks like this: xyz ---> did not smelt that metal Were we to contrapose this answer choice, it would put "did not smelt" on the left of the arrow, where it's useless to us.

  2. Unrelated to Goal3% picked this

    If a culture was unfamiliar with a metal, then it did not have a distinct

    To prove the conclusion we're trying to prove, we need a rule that looks like this: xyz ---> did not smelt that metal This answer doesn't have "did / didn't smelt" language in it at all, so it's useless to us.

  3. Unrelated to Goal2% picked this

    If a culture smelted copper and bronze, then it had distinct words for

    To prove the conclusion we're trying to prove, we need a rule that looks like this: xyz ---> did not smelt iron This answer does have "did / didn't smelt" language, but it's specifically about copper and bronze. You could use this answer to prove that a culture didn't smelt copper, bronze, or both. But we need a rule we can use to prove that iron wasn't smelted.

  4. If-Conclusion2% picked this

    If a culture did not smelt a metal, then it was unfamiliar

    To prove the conclusion we're trying to prove, we need a rule that looks like this: xyz ---> did not smelt that metal The conclusion is always on the right side of the arrow. This answer puts the conclusion into the "if" condition. Any time you see the conclusion on the left of the arrow, that answer is wrong. If you didn't know that fun fact, then here is how you might think about it -- you'd start by contraposing this answer choice, so that the right side of the conditional better lines up with some language from the conclusion. If a culture was ? then that culture familiar with a metal smelted that metal Could we apply this rule to the Sals, and then derive the conclusion that the Sals did not smelt iron? Well, iron is a metal. Were the Sals familiar with iron? Hmm. [re-read] It doesn't say. So we have no information that triggers this rule. Not to mention, if we thought that the Sals were familiar with iron, this rule would tell us that the Sals did smelt iron, which would contradict the conclusion we're trying to prove.

  5. Correct74% picked this

    If a culture smelted a metal, then it had a distinct word

    Why this is right

    To prove the conclusion we're trying to prove, we need a rule that looks like this: xyz ---> did not smelt that metal Our answer choice is providing this: did smelt a metal --> had a distinct word for it This answer is set up in contrapositive form, meaning the negation of the conclusion is on the left side of the arrow. Why? Because -- this is the correct answer. The test writers have to disguise its appeal, so they manipulate it into contrapositive form. We assess answers, on Sufficient Assumption and Principle, primarily for whether the answer choice has the Conclusion on the right side of the arrow, or whether it has the negation of the Conclusion on the left side. (E) as written: if you smelted it ? then had distinct word for it (E) contraposed: if you didn't have a distinct ? then you didn't word for a metal smelt that metal We were told, in the evidence, that the Sals didn't have a distinct word for iron, which is a metal. Thus, according to this rule, the Sals didn't smelt iron. We proved the conclusion! (and thank you, to LSAC, for this enjoyable homage to the classic childhood principle, 'if you smelt it, you dealt it')

    Skill tested: Sufficient Assumption · how this choice captures the argument's function is the move to repeat next time.

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