LSAT 146 | Section 3 | Logical Reasoning: Q2

LR Question 2 Explanation

QUESTION TEXT: An unstable climate was probably a major cause of the…

QUESTION TYPE: Strengthen

CONCLUSION: Climate instability probably was a significant cause of the Roman empire’s decline.

REASONING: Tree rings show that Europe’s climate had large fluctuations during the period the Roman empire declined. Climate fluctuations would have hurt agriculture, which would have made it harder to govern the empire and to defend it.

ANALYSIS: This already may seem like a good argument. But it’s a strengthen question, so you know it’s flawed. When a flawed argument seems good, you have to ask: how could this be wrong? If that doesn’t work, just go through the answers, but read all of them before you focus on any.

Personally, I didn’t spot that this argument made an implied comparison error. The author didn’t tell us about the climate before 250 A.D. Maybe the climate was also unstable them! The right answer strengthens the argument by eliminating this possibility.

___________

1. This is consistent with the argument, but it doesn’t really help it. We’re supposed to show that climate hurts agriculture. Political failures aren’t necessarily climate related.
2. This weakens the argument by breaking the link between climate instability and unrest. We’re supposed to strengthen the argument.
3. This is tempting, but it’s merely consistent with the argument. Poor farming practices don’t need to be due to climate. We’re supposed to show that climate is the cause.
4. CORRECT. This strengthens the argument by showing that the climate didn’t always fluctuate. If the climate had fluctuated during Rome’s rise, then the argument wouldn’t have been any good.
5. This weakens the argument slightly by showing that food production rose despite Rome’s fall. So it weakens the idea that: climate fluctuations ➞ lack of food ➞ Rome’s fall.