LSAT 135 | Section 2 | Logical Reasoning: Q25

LR Question 25 Explanation

QUESTION TEXT: Some people mistakenly believe that since we do not …

QUESTION TYPE: Principle – Application

ANALYSIS: The stimulus describes a general pattern:

1. We use present evidence to learn about the past.
2. That approach works.
3. But it becomes less useful the farther back in time we’re trying to learn about.

So we’re looking for another example that says: You can infer something about the past from present evidence, but those inferences become weaker the farther back you go.

The second half is crucial. Many wrong answers include only one half of the principle.

___________

1. CORRECT. This matches both parts of the principle. (1) Present-day evidence (recently collected data) is used to learn about the past. (2) But the farther back we go (the origin of the solar system), the less we can learn. That’s exactly the same pattern as the stimulus.
2. The second half is different here. The stimulus says usefulness decreases because the time period becomes more distant. This answer says that usefulness decreases because the evidence has already been examined repeatedly.
3. This isn’t about using present evidence to infer the past. It’s about cultural distance.
4. This is about making unjustified inferences. The stimulus is about making valid but increasingly limited inferences.
5. The first half matches (using present evidence to learn about the past). But the second half goes wrong. It says studying the evidence more increases understanding. The stimulus says studying the more distant past decreases what can be learned. Those are completely different ideas.