PrepTest 144
[lcid:3672] Prep Test 144 LSAT — Reading Comp — S1
Reading comp
Passage
. Passage A . Karl Popper's main contribution to the philosophy . of science concerns the power of negative evidence.
Remaining source text redacted.
Passage walkthrough
Passage SummaryTopic: Science
Passage A
Paragraph 1
Paragraph 1
Passage A - Popper's philosophy of science doesn't reflect the reality scientists face, especially with respect to the certainty with which negative evidence can disprove theories.
Passage B - When predicting the orbit of Uranus, scientists were correct in predicting a new planet, but in a similar situation with Mercury, it was actually Newton's laws that were shown to be incorrect.
Key Lines:
Passage A:
Lines 3-5 - An example makes a distinction much clearer
Lines 6-10 - A view is clarified and the Author calls it exaggerated ("hyperbolic")
Lines 17-19 - The Author criticizes the opposing view
Lines 30-32 - The Author clarifies her view, showing a shared viewpoint and an opposed viewpoint with the opposing point
Passage B:
Lines 41-44 - Alternative possibilities are discussed
Lines 48-51 - One possibility is shown to be correct
Lines 53-54 - A similar situation is raised
Lines 58-64 - A different possibility is shown to be correct in this example, with implications for the first
Meta-Structure - Relationship Between Passages:
Rebuttal (Passage A) - The Author of Passage A clearly thinks that Popper's philosophical contribution isn't 100% correct. However, she does clarify this at the end. Popper claims that positive evidence is inconclusive, but negative evidence is definitive in disproving a claim. The Author agrees that positive evidence is inconclusive (though she disagrees with Popper's view that it lacks all value), but she disagrees that negative evidence is always conclusive.
Comparisons (Passage B) - Passage B brings up two similar situations—planets are discovered, their orbits are predicted, and those predictions are wrong. However, the outcome of these situations is different. In the Uranus situation, it ended up being an auxiliary assumption (no other planets in the area) that was wrong. In the Mercury situation, it ended up being Newton's theories that were wrong.
Neutral Author (Passage B) - The Author of Passage B doesn't really take any sides or show any opinion. Rather, he focuses on presenting the details of two separate situations.
How do these passages relate? In a complicated manner! The first passage discusses an approach to scientific inquiry that revolves around positive and negative evidence. How does this apply to the two situations in Passage B? Well, in the Uranus case, the scientists used what they knew to predict an orbit, and that orbit turned out to be wrong. In other words, they made a prediction, and the evidence proved that prediction wrong—negative evidence!
In the Mercury example, they predicted an orbit that turned out to be wrong, so that's more negative evidence. They also then made a prediction that, similar to the Uranus situation, there would be another planet, but they didn't find one—also negative evidence!
(This was a lot of analysis, and we almost certainly wouldn't have walked through all of this ahead of heading to the questions. It's here to help you wrap your head around the passages!)
Also important to note is that the Author of Passage A talks about "auxiliary" assumptions, and Passage B brings these up as a possible place for a prediction made by a theory to go wrong. That overlap aligns the approach in Passage B with that of the Author over Popper.
Last Thoughts:
This comparative set is rough. It's hard to understand, abstract, and definitely outside of most people's area of expertise. So what can you do to make it easier? Rely on that example in Passage A, Paragraph 1. If we can understand what positive and negative evidence is, we should be able to muddle through the detail questions. And as for the Authors' viewpoints, Passage A has some clear statements of opinion, and Passage B lacks a particularly present author.
Passage A
Paragraph 1
- Paragraph note
- A philosopher is introduced, and his theory is explained in depth, focusing on a distinction
- Views, minor Meta-Structures, points of intersection, and the author's attitude
- Popper - Theory of negative evidence (vs positive evidence)
- Example - "All swans are white"
- Positive evidence - white swans (can't prove all are white); Popper says no value
- Negative evidence - black swan (one proves idea is wrong); Popper says disproves
- Author - Popper's view "hyperbolic"
- Popper - Negative evidence is core of science (scientific theory → makes predictions testable with negative evidence)
- Paragraph note
- The Author rebuts Popper's argument to some degree
- Views, minor Meta-Structures, points of intersection, and the author's attitude
- Author - Popper's view doesn't reflect scientific reality
- False prediction, premise of theory is wrong
- But which one? All theories have "auxiliary" premises from other theories and the real world (e.g., instruments work)
- Author - Popper is right to say positive evidence isn't conclusive; wrong to say negative evidence is
Paragraph 1
- Paragraph note
- A scientific situation is walked through
- Views, minor Meta-Structures, points of intersection, and the author's attitude
- Uranus orbit predictions were off, relied on Newton's laws, and auxiliary assumptions (including no other planets were nearby)
- Predictions wrong, so a premise must have been wrong
- Scientists tested other planets around, found that was the mistake
- Paragraph note
- A similar scientific situation is walked through
- Views, minor Meta-Structures, points of intersection, and the author's attitude
- Mercury orbit predictions were off, scientists predicted another planet (like with Uranus)
- No planet found, Einstein's new laws matched up with reality, so scientists rejected Newton's theory
Passage A - Popper's philosophy of science doesn't reflect the reality scientists face, especially with respect to the certainty with which negative evidence can disprove theories.
Passage B - When predicting the orbit of Uranus, scientists were correct in predicting a new planet, but in a similar situation with Mercury, it was actually Newton's laws that were shown to be incorrect.
Key Lines:
Passage A:
Lines 3-5 - An example makes a distinction much clearer
Lines 6-10 - A view is clarified and the Author calls it exaggerated ("hyperbolic")
Lines 17-19 - The Author criticizes the opposing view
Lines 30-32 - The Author clarifies her view, showing a shared viewpoint and an opposed viewpoint with the opposing point
Passage B:
Lines 41-44 - Alternative possibilities are discussed
Lines 48-51 - One possibility is shown to be correct
Lines 53-54 - A similar situation is raised
Lines 58-64 - A different possibility is shown to be correct in this example, with implications for the first
Meta-Structure - Relationship Between Passages:
Rebuttal (Passage A) - The Author of Passage A clearly thinks that Popper's philosophical contribution isn't 100% correct. However, she does clarify this at the end. Popper claims that positive evidence is inconclusive, but negative evidence is definitive in disproving a claim. The Author agrees that positive evidence is inconclusive (though she disagrees with Popper's view that it lacks all value), but she disagrees that negative evidence is always conclusive.
Comparisons (Passage B) - Passage B brings up two similar situations—planets are discovered, their orbits are predicted, and those predictions are wrong. However, the outcome of these situations is different. In the Uranus situation, it ended up being an auxiliary assumption (no other planets in the area) that was wrong. In the Mercury situation, it ended up being Newton's theories that were wrong.
Neutral Author (Passage B) - The Author of Passage B doesn't really take any sides or show any opinion. Rather, he focuses on presenting the details of two separate situations.
How do these passages relate? In a complicated manner! The first passage discusses an approach to scientific inquiry that revolves around positive and negative evidence. How does this apply to the two situations in Passage B? Well, in the Uranus case, the scientists used what they knew to predict an orbit, and that orbit turned out to be wrong. In other words, they made a prediction, and the evidence proved that prediction wrong—negative evidence!
In the Mercury example, they predicted an orbit that turned out to be wrong, so that's more negative evidence. They also then made a prediction that, similar to the Uranus situation, there would be another planet, but they didn't find one—also negative evidence!
(This was a lot of analysis, and we almost certainly wouldn't have walked through all of this ahead of heading to the questions. It's here to help you wrap your head around the passages!)
Also important to note is that the Author of Passage A talks about "auxiliary" assumptions, and Passage B brings these up as a possible place for a prediction made by a theory to go wrong. That overlap aligns the approach in Passage B with that of the Author over Popper.
Last Thoughts:
This comparative set is rough. It's hard to understand, abstract, and definitely outside of most people's area of expertise. So what can you do to make it easier? Rely on that example in Passage A, Paragraph 1. If we can understand what positive and negative evidence is, we should be able to muddle through the detail questions. And as for the Authors' viewpoints, Passage A has some clear statements of opinion, and Passage B lacks a particularly present author.
Question prompt
In passage B's description
Remaining source text redacted.
Why the credited answer is right
Credited answer: A
The notes below walk through why it fits the stem and how to eliminate the rest.
Question Type
Science
Answer choices
-
AMercury
Why choice A matches the stem
Correct. Question Type:
Parallel Reasoning
Strategy Overview:
Define the elements in the black swan example, then line up the analogous elements in Passage B
Answer Anticipation/Relevant Lines:
Let's start by getting a handle on the black swan example. There, a "theory" was put forward—all swans are white. Then, a single black swan was shown to be sufficient to disprove the theory.
So what's the theory in Passage B that ends up disproven? Newton's theory of gravity. And what body was used to disprove that theory? It must be one of the bodies in the Mercury example, and only Mercury and Vulcan are discussed. But in Passage A, the black swan's existence disproved the theory, and Vulcan wasn't shown to exist. Additionally, if Vulcan did exist, it would have strengthened the argument for Newton's theory, since then that theory would have correctly predicted the orbit of Mercury. So Mercury, in existing and having a certain orbit that doesn't line up with Newton's theory, is used to disprove that theory. That makes Mercury the black swan equivalent, so let's find that as an answer.
Answer Explanation:
(Lines 62-63) Mercury's orbit (with the auxiliary assumptions) didn't match up with the predictions generated by Newton's theory of gravity, and that was enough in Passage B for scientists to reject the theory. The existence of the black swan in Passage A was sufficient to reject the claim that all swans are white. Thus, mercury and the black swan both serve as negative evidence sufficient to disprove a theory, and thus this is the correct answer.
Key Takeaway:
In Parallel Reasoning questions for RC, always line up the elements! If you do that and have a misalignment, you'll know that you've got the lined up wrong and should work through your matches again. -
BUranus
Why choice B is not credited
Incorrect. (Lines 43-51) After positing the existence of Neptune, Newton's theories correctly predicted both the orbit of Uranus and the location of Neptune. That's positive evidence for Newton's laws, not negative evidence against them, as the black swan was in Passage A. -
CNeptune
Why choice C is not credited
Incorrect. (Lines 43-51) The existence of Neptune brought the orbit of Uranus in line with Newton's theory of gravity, and so it didn't serve as negative evidence against that theory, unlike the black swan in Passage A. -
DVenus
Why choice D is not credited
Incorrect. Be careful! The passage didn't mention Venus—it mentioned Vulcan. (And even if this answer said Vulcan, the existence of Vulcan would line up with Newton's theories, allowing them to explain Mercury's orbit, so Vulcan would be akin to Neptune and wrong for the exact same reason.) -
Ethe sun
Why choice E is not credited
Incorrect. (Lines 35-37) The mass of the sun was one of the auxiliary assumptions made to calculate the orbits of Mercury and Uranus, and there's no sign that it served as negative evidence or was wrong.
What this tests
Discussion
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Please explain 1 reply
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Neptune 1 reply
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