#9 - Astronomer: Proponents of the hypothesis that life

[Administrator]

Complete Question Explanation

Flaw in the Reasoning. The correct answer choice is (A)

The stimulus has a convoluted argument/counterargument structure, and the astronomer’s conclusion does not become apparent until the last sentence. Nevertheless, whenever the stimulus begins by outlining someone else’s position (the “proponents,” in this case), you should expect that the author will ultimately disagree with it.

The stimulus, when simplified, has the following structure:

• Proponents:
  
  Premise (1): 3.8 billion years ago, Earth was bombarded by meteorites that would have destroyed any life in it.
  
  Premise (1): 3.5 billion years ago, Earth had life forms that could not have evolved in only 0.3 billion years.
  
  Conclusion: Life evolved extraterrestrially and drifted here in spores from outer space.
  
  Astronomer:
  
  Premise: The proponents merely offer empirical arguments against the view that life evolved on Earth, instead of positive proof in favor of the extraterrestrial-spore theory.
  
  Conclusion: The proponents’ hypothesis is false.

Both arguments are inherently flawed, and both commit errors in the use of evidence. The proponents offer empirical arguments against the view that life evolved on Earth, but fail to establish with any certainty that life drifted here in spores from outer space. In other words, they mistakenly assume that some evidence against a hypothesis proves the truth of a competing hypothesis. The astronomer is guilty of a similar flaw: he interprets the proponents’ failure to provide evidence in favor of a given theory as evidence that their theory is false.

The flaws in both arguments are summarized below:

• Proponents: Some evidence against a hypothesis is taken to prove the truth of a competing hypothesis.
  
  Astronomer: Lack of evidence for a hypothesis is taken to prove that hypothesis false.

Answer choice (A): This is the correct answer choice. As discussed above, the astronomer interprets the proponents’ failure to provide evidence in favor of their hypothesis as evidence against their hypothesis. This is a classic error in the use of evidence, and should be prephrased.

Answer choice (B): There is no reason to believe that the astronomer views the proponents’ hypothesis as “inherently implausible.”

Answer choice (C): The astronomer does not comment on the plausibility of any hypothesis other than the extraterrestrial-spore theory.

Answer choice (D): Just because the astronomer contradicts the proponents of the extraterrestrial-spore theory does not mean that his argument is guilty of self-contradiction.

Answer choice (E): Indeed, the astronomer does not reject the claims made in support of the extraterrestrial-spore theory, but that does not amount to a logical flaw: most counterarguments on the LSAT assume that the opponent’s premises are factually accurate.

[sherpower]

Hi, isn't the answer choice B, the "inherently implausible" a loose interpretation of "false"? I thought about it as correct, as the author fails to justify his view that the hypothesis of the proponents is false, as he doesn't prove it to be false, but merely presents arguments against it (that the other side has not offered "positive evidence."

Also, with A, I don't see how he believes that the lack of evidence is interpreted to be evidence against the hypothesis, which even if it were the case, it would not prove that the hypothesis is false, which is the author's conclusion. In other words, A is not the logical equivalent of "false" on the hypothesis characterization. We would need to make the same evidence use logic error with the author to equate the evidence against with the hypothesis being false.

Let me know what you think.

[Claire Horan]

Hi Sherpower,

The phrase "inherently implausible" is much more extreme than false, and you should look out for extreme answer choices.

For example, you may believe that I went to the movies yesterday. That is not an inherently implausible belief. I sometimes go to the movies, so it's not unlikely that I would have gone. But it would be a false belief because, in fact, I didn't go.

"Inherently implausible" means something like "essentially unreasonable or improbable." The astronomer doesn't say the spore theory is false because it is so unlikely that spores could travel here and survive or anything like that. He argues that "there is good reason" to disregard the theory because there is no positive evidence in support of it.

The reason that (A) correctly describes the astronomer's flawed argument is that he says "there is good reason to regard their hypothesis as false." That is an assertion that there is "evidence against the hypothesis." That evidence is what the astronomer mentions next, that there is no positive support for the theory. The astronomer, thus, argues that the lack of positive support for the theory is evidence against the theory.

I hope this helped!

[JD180]

First and foremost, the astronomer says "good reason to regard their hypothesis is false." he does not say "good EVIDENCE to regard their hypothesis is false." You can't introduce evidence unless you equivocate reasoning with evidence, which is absurd

The Astronomer interprets the proponent's failure, not as evidence against his hypothesis, but as reasoning against his hypothesis (reasoning that doesn't suggest falsehood at that), and if this is what A would have said, I would have selected it.

Unfortunately, A does not say this. Here is another problem - A says and I am quoting, "concludes, simply because there is no evidence in favor of a hypothesis, THAT THERE IS evidence against that hypothesis."

If your explanation were correct (believe me, I wish it were), then A would have said "concludes, simply because there is no evidence in favor of a hypothesis, THAT THIS IS evidence against that hypothesis." If this were said, then A is O.K. But even then, he explicitly says in the stimulus that there is GOOD REASON to regard the hypothesis as false. Thus, A really should read "concludes, simply because there is no evidence in favor of a hypothesis, he reasons the hypothesis is false."

Overall, two problems with the question: (1) THERE IS vs. THIS IS and (2) GOOD REASON =/= EVIDENCE

I'm not too concerned with (1), because there is an avenue where There Is and This Is are the same. For example, If I were to say "There is evidence, and This is it!" So I can see why one would reject my assertion about (1). I maintain that saying "There is" is a very awkward way to write, and a lazy way to challenge students - but lazy is subjective so I'll stick with number (2) as my repudiation of the question.

B is tempting, but false and implausible have two different definitions. Implausible this means dubious or doubtful about something (or not probable). This is weaker than "false". Also, "inherently implausible" is word salad - no thanks.

I selected A, but I was laughing as I selected it. You have to know when the test-makers are in over their heads, and that just takes a lot of practice and dissecting every question to the McGees.

Man, when I write the LSAT, I sure hope its written well, otherwise LSAC Pennsylvania will be getting several calls from a disgruntled test-taker.

[Sky Brooks]

Hi JD180,

I see that this question seems to have been a bit frustrating. To address the astronomer's statement, "There is good reason to regard their hypothesis as false, however, for they merely offer empirical arguments against the view that life evolved on Earth"... I don't think that reasoning is being equivocated with evidence. The astronomer is basically making the claim that there is a valid reason to regard the hypothesis as false, due to the existence of some evidence.

I also disagree with your point about "there is" vs. "this is" in regards to the wording in answer choice A.
The correct answer states:
(A) concludes, simply because there is no evidence in favor of a hypothesis, that there is evidence against that hypothesis

It may make it easier for readers to understand that the actual lack of evidence in support of the hypothesis, is what's being cited as the sufficient evidence against it, but that doesn't need to be discerned for choice A to be a true statement. The flaw in the reasoning is that the astronomer claims there is reason to reject the hypothesis, but really, there is just a lack of evidence in support of it.

-Sky Brooks

[JD180]

Hi JD180,

I see that this question seems to have been a bit frustrating. To address the astronomer's statement, "There is good reason to regard their hypothesis as false, however, for they merely offer empirical arguments against the view that life evolved on Earth"... I don't think that reasoning is being equivocated with evidence. The astronomer is basically making the claim that there is a valid reason to regard the hypothesis as false, due to the existence of some evidence.

I also disagree with your point about "there is" vs. "this is" in regards to the wording in answer choice A.
The correct answer states:
(A) concludes, simply because there is no evidence in favor of a hypothesis, that there is evidence against that hypothesis

It may make it easier for readers to understand that the actual lack of evidence in support of the hypothesis, is what's being cited as the sufficient evidence against it, but that doesn't need to be discerned for choice A to be a true statement. The flaw in the reasoning is that the astronomer claims there is reason to reject the hypothesis, but really, there is just a lack of evidence in support of it.

-Sky Brooks

Hi Sky,

You misinterpreted what I said. ANSWER A mentions "evidence", but the STIMULUS refers to ONLY reasoning. Thus, in the ANSWER A, they must mean that evidence=reasoning

[Dave Killoran]

First and foremost, the astronomer says "good reason to regard their hypothesis is false." he does not say "good EVIDENCE to regard their hypothesis is false." You can't introduce evidence unless you equivocate reasoning with evidence, which is absurd

While I don't think this line of discussion is productive since (A) is the correct answer, if we entertain your argument on the above point, I'll note you've rather narrowly interpreted "reason" here. If an author says "there is good reason," that could easily be seen as "there is a good reason," or, there is good evidence. But regardless, what occurred here is that you looked to justify your view instead of looking to understand theirs, and that's a point I've made before in prior responses to your questions. As I've said before, you can't argue with the LSAT. Or rather, you can, but it isn't productive and not something we'll spend a lot of time engaging in.

If your explanation were correct (believe me, I wish it were)

Our explanation is correct; it explains what the test makers were thinking and why they determined (A) is the correct answer.

Man, when I write the LSAT, I sure hope its written well, otherwise LSAC Pennsylvania will be getting several calls from a disgruntled test-taker.

Calling won't do anything. You'll have to submit a written statement about the disputes as outlined here: Policies and Procedures Governing Challenges to LSAT Questions. In a case such as the above, you'd lose immediately as they will say (A) is the one and only one best answer. They'll also say it's clear and unambiguous, which I'd agree with.