Reading ComprehensionDifficulty: Hard

PT140 S4 P4 Q22 Explanation

Explaining Mirror Images

A free, expert breakdown of this official LSAT Reading Comprehension question.

TopicsLocate DetailScience

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Passage

Physicists are often asked why the image of an object, such as a chair, appears reversed left-to-right rather than, say, top-to-bottom when viewed in a mirror. Their answer is simply that an image viewed in a mirror appears reversed about the axis around which the viewer rotates his or her field of sight about a vertical axis, mirror images usually appear reversed left-to-right. This is the field-of-sight explanation.

However, some physicists offer a completely different explanation of what mirrors “do,” suggesting that mirrors actually reverse things front-to-back. If we place a chair in front of a mirror we can envision how its reflected image will appear by imagining another chair in the space “inside” the mirror. The resulting reflection is explanation treats it as though it were as real and three dimensional as the original chair.

This explanation appeals strongly to many people, however, because it is quite successful at explaining what a mirror does—to a point. It seems natural because we are accustomed to dealing with our mental constructs of objects rather than with the primary sense perceptions on which those constructs are based. In general, we our eyes; rather, we look into them, with our focal lengths adjusted into the imagined space.

In addition to its intuitive appeal, the front-to-back explanation is motivated in part by the traditional desire in science to separate the observer from the phenomenon. Scientists like to think that what mirrors do should be explainable without reference to what the observer does (e.g., rotating a field of sight). However, questions longer addressing images and appearances, because an image entails an observer and a point of view.

What this question is testing

Locate Detail

Your task

Pin down exactly what the question asks about the passage — a detail, the author's view, the structure, or the main point — before looking at the choices.

Common trap

Answers that restate a true detail from the passage but don't answer the specific question being asked.

Winning move

Anticipate the answer in your own words from the passage, then find the choice that matches that prediction.

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

The question
22.

According to the passage, the fact that we are accustomed to dealing with our mental constructs rather than the primary sense perceptions on which those constructs are

Answer choices

  1. Out of Scope: top-to-bottom explanation7% picked this

    accept the top-to-bottom explanation of what

    There isn't ever a top-to-bottom explanation discussed in the passage, just field-of-sight and front-to-back.

  2. Correct66% picked this

    understand the front-to-back explanation of what

    Why this is right

    The 2nd sentence of the 3rd paragraph is saying that "the front-to-back explanation" appeals strongly and seems natural because we're accustomed to dealing with constructs not perceptions. So being accustomed to dealing with constructs, not perceptions, facilitates the natural, intuitive appeal of the front-to-back explanation. This answer requires that we stretch from "people find it appealing / it seems natural / its intuitive appeal (beginning of 4th paragraph" to the answer choice's phrasing of "facilitates understanding". It's not a perfect match, but it's the closest we're offered. It's easier to understand something that's intuitive and feels natural than to understand something that's surprising or counterintuitive.

    Skill tested: Locate Detail · how this choice captures the passage's function is the move to repeat next time.

  3. Out of Scope: challenge explanations10% picked this

    challenge complex explanations of common perceptual

    This answer choice is saying that because people are accustomed to dealing with their mental constructs rather than their primary perceptions, they're better able to fight scientists when it comes to challenging the scientists' complex explanation of a perceptual observations? It's probably fair to say that being accustomed to constructs not perceptions increases our likelihood of fighting someone with a more challengingly complex explanation of how mirrors work, but that's different from saying it helps us to be able to challenge complex explanations. More importantly, the passage is never talking about ordinary people challenging complex explanations. They might find such explanations less intuitively appealing, but nothing here is saying that they actively try to rebut those explanations.

  4. Opposite11% picked this

    reject customarily reliable equations between perceptions and their associated

    We're accustomed to dealing with constructs, not perceptions, because we accept the customarily reliable equation between the two.

  5. Unsupported5% picked this

    overemphasize the fact that mirrors simulate sense impressions

    I don't know where to begin with this word salad. It's incredibly awkward to say "X facilitated my ability to overemphasize ... " Who ever lacks the ability to overemphasize? We're free to overemphasize anything whenever we'd like to. That's free speech. So that verb is already an answer-killer. But could we even say that "it's a fact that mirrors simulate sense impressions of objects"? No, that doesn't make any sense either. Maybe an artificial intelligence computer could simulate sense impressions. Mirrors are an object that provide us cognitive beings with our sense impressions. They aren't simulating sense impressions. Because our perception / mental construct of the image in a mirror is one with depth, we could say that our mental construct of what we're seeing is simulating depth when it perceives the mirror's surface. Taking a big step back, this answer seems to even say the opposite of what the passage is saying. Because we deal with constructs not perceptions, we find the front-to-back explanation naturally appealing, which means we're under-emphasizing or failing to recognize that we're only pretending / simulating the idea that images in mirrors have depth.

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