PT38.S3.Q05 - the myth persists

brigitte

This is a pretty easy question IMO, but I have a question about why (E) is wrong and the interpretation of "or".

The author of the passage provided Nicaraguan pines as an example of a forest produced in part through controlled burning. The author does not think the pines were produced by natural fires. So the most straightforward explanation for why (E) is wrong is that the author would not agree that the Nicaraguan pines "could have been created by natural fires or controlled burning" because (s)he disagrees with natural fires as the cause.

But consider this: Let's say we know that A is true, and that B is not true. Given that information, can I logically conclude that "Either A is true or B is true"? I submit that the answer is yes. Because we know that A is true, it's a true statement to say that "A is true or B is true." For example, let's say I'm a senior in college. Someone asks me what year I am. I respond, "I am either a junior or senior in college." What I said in response is logically true even though I am not a junior. Or, let's say today is Wednesday. Someone asks what day it is. I say "It's either Wednesday or Thursday." That is a true statement, even though it's not Thursday.

So returning to answer choice (E), if the author's point is that the Nicaraguan pines were produced by controlled burning, then wouldn't the author logically HAVE TO AGREE that the fires could have been created by controlled burning or natural fires? Even if they weren't created by controlled burning, they were created by natural fires. So in the same sense that "I am a junior or senior" is true even if I am only a senior, "Created by controlled burning or natural fires" must be true even if it's just controlled burning. Why is this analysis wrong?

Does it have anything to do with the "could have been created by either" aspect of the answer choice? Some might think that the answer choice is not using "or" in the exact same way as "I am a junior or senior", because whereas that statement is equivalent to asserting that "I am at least one of the following things: junior or senior", the claim that the pines "could have been created by either natural fires or controlled burning" is asserting that both parts of the OR are definitely potential explanations, rather than the idea that "at least one of these explanations is correct". Is that what explains why (E) is wrong? If so, can someone elaborate on the grammatical or contextual rules governing the meaning of "or" in this situation?

https://7sage.com/lsat_explanations/lsat-38-section-3-passage-1-questions/

akistotle

@anonclsstudent said:
The author of the passage provided Nicaraguan pines as an example of a forest produced in part through controlled burning. The author does not think the pines were produced by natural fires. So the most straightforward explanation for why (E) is wrong is that the author would not agree that the Nicaraguan pines "could have been created by natural fires or controlled burning" because (s)he disagrees with natural fires as the cause.

I agree with this. I couldn't infer from the passage that Nicaraguan pine forests could have been created by natural fires.

So returning to answer choice (E), if the author's point is that the Nicaraguan pines were produced by controlled burning, then wouldn't the author logically HAVE TO AGREE that the fires could have been created by controlled burning or natural fires?

Why is this so? The author may not agree that Nicaraguan pines were created by natural fires. They could have been created by something else.

So in the same sense that "I am a junior or senior" is true even if I am only a senior, "Created by controlled burning or natural fires" must be true even if it's just controlled burning.

I may be wrong, but I think you can't say that you are a junior or senior when you are definitely a senior.

/Junior → Senior

If you are "Senior," this satisfies the necessary condition and the rule goes away.

brigitte

@akistotle said:

@anonclsstudent said:
The author of the passage provided Nicaraguan pines as an example of a forest produced in part through controlled burning. The author does not think the pines were produced by natural fires. So the most straightforward explanation for why (E) is wrong is that the author would not agree that the Nicaraguan pines "could have been created by natural fires or controlled burning" because (s)he disagrees with natural fires as the cause.

I agree with this. I couldn't infer from the passage that Nicaraguan pine forests could have been created by natural fires.

So returning to answer choice (E), if the author's point is that the Nicaraguan pines were produced by controlled burning, then wouldn't the author logically HAVE TO AGREE that the fires could have been created by controlled burning or natural fires?

Why is this so? The author may not agree that Nicaraguan pines were created by natural fires. They could have been created by something else.

So in the same sense that "I am a junior or senior" is true even if I am only a senior, "Created by controlled burning or natural fires" must be true even if it's just controlled burning.

I may be wrong, but I think you can't say that you are a junior or senior when you are definitely a senior.

/Junior → Senior

If you are "Senior," this satisfies the necessary condition and the rule goes away.

If I am a senior, why wouldn't it have to be true that I am either a Junior or Senior? Even though I am not a junior, I still am senior, so I have satisfied the truth of the statement "Junior or Senior".