Logical Reasoning

PT14 · S4 · Q25 In Peru, ancient disturbances in the dark

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In Peru, ancient disturbances in the dark surface material of a desert show up as light‐colored lines that are the width of a footpath and stretch for long distances.

Curious Fact

There are ancient lines in the Peruvian desert. They form path-like lines. Some of them branch out like rays from a single point and cross over curved lines that form a very large bird figure.

Investigator's Explanation

These lines were landing strips for alien spaceships (after all, the Inca would have no use for spaced roads that ran parallel, or for roads that intersected in a sunburst pattern, or that came abruptly to an end in the middle of a desolate plain).

Alternate Explanation

These lines refer to astronomical phenomena.

Potential Objection to This

Wait a sec ... doesn't the fact that the straight-line pattern crosses over the bird figure show that these two sets of lines are not serving the same purpose?

Goal

We're supposed to find an answer that lets the Astronomical guy say,

(note: if you feel like you're going crazy because it was nearly impossible to discern the task that LSAT was assigning us, you're not. This question stem is incredibly confusing to interpret.)

25.

For someone who interprets the lines as referring to astronomical phenomena, which one of the following, if true, most effectively counters an objection that the crossing of the straight-line pattern over the bird figure shows that the two kinds of line pattern served unrelated purposes?

  1. In areas that were inhabited

    Very Weak Impact

    This is sort of corroborating the plausibility of the hypothesis that ancient lines in the sand in South America were meant to refer to astronomical phenomena. How? It's saying, "there are other things (arrangements of stones) used in other places (North America) in ancient times that referred to astronomical phenomena." But that's incredibly loosely related, so it's barely doing any support.

    8% picked this

  2. Correct

    The straight lines are consistent

    Why this is right

    This answer allows us to argue that all these lines served the same purpose, of referring to astronomical phenomena. The straight lines showed people where to look in order to observe certain astronomical events, and the bird looking thing was a representation of a constellation. "Even though the straight lines and the bird seem like very different and incompatible designs, they are both related to the same purpose (referring to astronomical phenomena)."

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

    64% picked this

  3. The straight-line pattern is part

    No Impact

    This only talks about the straight-lines, so it doesn't accomplish our goal of explaining to this objector how both the straight-lines and the bird figure could both be related to astronomical phenomena.

    14% picked this

  4. Native Central American cultures, such

    Very Weak Impact

    This is like (A). It adds a modicum of plausibility of the hypothesis that ancient lines in the sand in South America were meant to refer to astronomical phenomena. How? By saying, "there are other things (rock engravings) used in other places (Central America) in ancient times that referred to astronomical phenomena." But that's very loosely related, so it's barely doing any support.

    3% picked this

  5. There is evidence that the

    Weakens, if anything

    This answer doesn't help us with our goal of arguing that the bird figure and the straight-line pattern are both meant to refer to astronomical phenomena. If anything, the fact that the bird figure was made well before the straight-line pattern would help our enemy argue that these are two unrelated things that did not serve the same purpose.

    11% picked this

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