#2 - Archaeologist: For 2,000 years the ancient Sumerian

[Dancingbambarina]

Sharon mentions how the alternate cause in B does not weaken the arhument. How is this so? In the book, it says the Author believes only one cause to cause the effect. Am I right there is a CAUSAL assumption here that irrigation over time causes society to collapse? If so, surely B underminies the causal relationship?

[Luke Haqq]

Hi Dancingbambarina!

There does seem to be a causal argument to that effect in the stimulus. However, note that what you're supposed to weaken is the conclusion of the argument. That is the final sentence: "A similar fate is thus likely to befall modern civilizations that continue to rely heavily on irrigation for agriculture." Something that shows, for example, that a similar fate isn't likely to befall modern civilizations would weaken that argument. That is what answer choice (C) does.

Answer choice (B) just raises some counterfactual information that doesn't really get to whether or not modern civilizations are likely to face a similar fate. Even if (B) were true, it's still the case that the Sumerian civilization did collapse because of the reasons given in the stimulus, reasons which seem relevant to modern civilizations that continue to rely heavily on irrigation for agriculture.