Q5 - Irrigation runoff from neighboring farms

[jimmy902o]

Im not sure if its that I dont understand the argument, but I cant see why C is correct. if people drink the water then it should be safe for aquatic wildlife right? how is this irrelevant?

[justsammyy]

I'm not sure if I'm entirely right (because I actually just searched this myself to find out haha) but I think the flaw is that the conclusion is saying that the "damage to aquatic life is false" and then provides evidence about humans being able to drink the water to support his conclusion.

It's a little weird that he would provide two totally different things (humans/fish) and just assume that if it's okay for one, then it's okay for the other. In other words, it has never been established in the stimulus whether people being able to drink the water makes it okay for aquatic life to be safe from the increase in phosphorous levels.

Hope that helps

[bbirdwell]

if people drink the water then it should be safe for aquatic wildlife right?

Great thought! The short answer is "No!"

The longer answer is, "not necessarily -- the argument has to actually STATE that relationship."

I say it's a great thought to have because what you've done by asking that question is identify a NECESSARY ASSUMPTION. Keep honing that skill, and understand that if the argument does not provide explicit reasons to answer "yes" to that kind of question, you have identified an assumption, which can help you answer assumption, flaw, strengthen/weaken, and principle questions. It's perhaps THE fundamental LSAT skill.

[roflcoptersoisoi]

Premise: The phosphorus concentration in the swap is less than that found in certain kinds of bottle water that some people drink everyday
Conclusion: The claim the the increase in phosphorus levels in the swamp harm it's native aquatic life is false

Takes for granted that the concentration of phosphorus in bottled water is not dangerous to aquatic life. Perhaps it's not dangerous to people but it's dangerous to other species.
Fails to consider that the amount of phosphorus in the swamp level may be at a dangerous level even if it's concentration is less than that in bottled water.
In all we simply do not know enough about the effects of the phosphorus concentration in the bottled water.

(A) It doesn't embellish or exaggerate anything in his argument
(B) The premises are no contradictory. He concedes an opposing point and then he makes his argument
(C) Bingo
(D) The author is not using circular reasoning
(E) Tempting. He doesn't specify where he got the empirical data, but that is not why the argument is in error.

[VendelaG465]

is E wrong because it is attacking the premise( which is the data on the water bottles)?

[ohthatpatrick]

Yeah, that's one way of saying it.

Another way to say why (E) is wrong is that we shouldn't be reacting to this logic by saying,
"Wait a sec ... why should I believe that the swamp's phosphorous concentration is less than that found in bottled water? Who did these measurements?!"

We SHOULD be reacting to the logic by saying,
"Why should I believe that the uptick in Phosphorous is fine for the swamp's wildlife, just because it's okay for humans in bottled water?"

The latter question is the one that (C) is addressing.

We're always accepting the premises for what they are. We're thinking, "assuming the evidence is true, how could the conclusion still be wrong?"