#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.

[jk3530]

I was torn btw B and C and chose B . My thinking was that in weakening questions, sometimes the correct answer doesn't necessarily attack the link btw the premise and conclusion but can weaken the premise itself. If the collapse of the Sumerian civilization wasn't actually caused by irrigation, then wouldn't the whole basis for drawing a parallel to modern civilizations also weaken?

I'm also confused about C because the conclusion specifically talks about "modern civilizations that rely heavily on irrigation for agriculture" not all modern civilizations. What if these modern farmers in C aren't representative of those civilizations? Then C might not be directly relevant to the conclusion's scope?

Thank you

[Luke Haqq]

Hi jk3530!

I wouldn't say that the whole basis for warning for modern civilizations would be weakened even if the collapse of the Sumerian civilization wasn't actually caused by irrigation. Even if we assumed that it collapsed for some other reason (such as disease or warfare), we're still left with the information given that irrigation leads to toxic levels of salt that make it unable to support agriculture.

So the claim that Sumerian civilization probably would have collapsed from other causes sooner or later, as (B) supposes, doesn't weaken the argument that it in fact collapsed because its irrigation practices made its soil unable to support agriculture. In addition, presumably civilizations today would also want to avoid depending on irrigation to avoid that fate. Here you might be able to prephrase some objections--for example, perhaps people today have access to technologies that prevent the buildup of toxic levels of salt. That's effectively what (C) is saying--it's saying that new techniques have been developed that deal with the issue that had previously led to the Sumerian civilization's collapse.