LSAT Explanation PT 43, S3, Q16: Everything that is commonplace and ordinary

LSAT Question Stem

The conclusion of the argument follows logically if which one of the following is assumed? 

Logical Reasoning Question Type

This is a Sufficient Assumption question. 

Correct Answer

The correct answer to this question is B. 

LSAT Question Complete Explanation

First, let's analyze the argument in the passage. The passage states that everything that is commonplace and ordinary fails to catch our attention, and there are things that fail to catch our attention but are miracles of nature. To better understand this, let's use a simple example. Imagine a tree in a park. It's quite ordinary and commonplace, so it might not catch our attention. However, the tree could be considered a miracle of nature due to its intricate growth process and ability to provide oxygen.

The argument structure can be broken down as follows:

Premise: Commonplace and ordinary things (CO) fail to catch our attention (COA).

Conclusion: There are things that fail to catch our attention (COA) but are miracles of nature (MN).

Now, let's create an "Evaluate" question about the argument: "What is the relationship between miracles of nature and things that are ordinary and commonplace?"

The question type for this problem is Sufficient Assumption, which asks us to find an assumption that, if true, would make the conclusion follow logically from the premise. Let's analyze each answer choice:

a) Only miracles of nature fail to be ordinary and commonplace.

This answer choice can be diagrammed as CO -> /MN. Combining this with the contrapositive of the premise, we get COA -> CO -> /MN, which means if something catches our attention, it is a miracle of nature. This does not match the conclusion of the passage, so this answer choice is incorrect.

b) Some things that are ordinary and commonplace are miracles of nature.

This answer choice can be diagrammed as CO -> MN. Since "some" statements are reversible, we can reorder and combine this with the premise: MN -> CO -> COA. The relationship becomes "Some miracles of nature will fail to catch our attention," which is logically equivalent to the conclusion. Therefore, this answer choice is correct.

c) Some things that are commonplace and ordinary fail to catch our attention.

This answer choice is an inherent inference of the premise and does not explain the relationship between miracles of nature and things that fail to catch our attention. It cannot be the correct answer.

d) Everything that fails to catch our attention is commonplace and ordinary.

This answer choice can be diagrammed as COA -> CO, which is a Mistaken Reversal of the premise. However, it does not explain the relationship between miracles of nature and things that fail to catch our attention, so it cannot be the correct answer.

e) Only extraordinary or unusual things catch our attention.

This answer choice can be diagrammed as CO -> /COA, which is a Mistaken Negation of the premise. However, it does not clarify the relationship between miracles of nature and things that fail to catch our attention, so it is not the correct answer.

In conclusion, the correct answer choice is (b) Some things that are ordinary and commonplace are miracles of nature. This assumption establishes the proper relationship between miracles of nature and things that are ordinary and commonplace, making the conclusion logically follow from the premise.