Q1 - Freshwater Supply

[ohthatpatrick]

Question Type:
Necessary Assumption

Stimulus Breakdown:
Conclusion: In order to meet the freshwater needs of the near future, we'll have to restrict water use.
Evidence: The population will increase a ton over the next few decades, drastically increasing our need for freshwater (our supply is adequate for present use).

Answer Anticipation:
Given that we will have drastically increasing demand for freshwater, how would we counterargue that we WON'T have to restrict water use to meet our freshwater needs? Not sure. I guess there just must be some way besides restricting water use that will allow us to meet our needs. Since this is Necessay Assumption, the correct answer when negated will crush the argument.

Correct Answer:
C

Answer Choice Analysis:
(A) "Other natural resources" is out of scope.

(B) We don’t care about the recent past; we care about the near future. If you negated this and said "total freshwater supply HAS diminished in recent years", that makes it even more likely that the author is right about us needing to restrict water in the near future.

(C) Yes! This has the loveable "ruling out" language that is in so many correct Nec Assump answers. When we negate this, it says that "freshwater supply WILL increase sufficiently to meet the newly increased needs of humankind". That blows up the conclusion. We will NOT need to restrict water use if our supply will increase sufficiently to meet our needs.

(D) This is pretty extreme, but still somewhat tempting. if we negated it, we're saying "some attempt to synthesize water WILL have an appreciable effect on freshwater supply". That's kinda like what we got in (C): freshwater supply will go up. However, in (C) we got language that fully guarantees that supply goes up enough to compensate for the increased needs of humanity. In (D), we get no such wording. Thus, comparing them head-to-head makes (C) a clear winner.

(E) This is extreme. If we negate it, it's saying "at least one water conservation method we've previously attempted DID yield an increase in freshwater supply." It would be a LOT of added thoughts to think that we can get from that idea to the idea that "we won't need to restrict water because we'll have ample supply".

Takeaway/Pattern: Some people will "hear" what wasn't said when they read this argument. It is said that the present freshwater supply is adequate for today's use. It is assumed that the present (or future) freshwater supply will NOT be adequate for our future water needs. The rest of us should just use the negation test as we always do on Necessary Assumption, in which case we can see how (C), when negated, basically blows up the argument.

#officialexplanation

[nandy_millette]

So, Assumption family questions are killing me because I always fail to recognize the flaw and end up using POE or Negation Test or some other back end strategy.

My goal is to work on my ability to identify and articulate the Flaw in all Assumption family questions. So, I would appreciate some feedback on my current strategy.

Premise: the human population will increase thereby causing an increased need for freshwater

Conclusion: Restrictions on fresh water will be necessary to meet the demands of humans

Flaws:
The author is failing to consider
1) restriction on fresh water is the only way to deal with the increased demand
2) the author is assuming that the water supply would not increase substantially naturally thereby catering to the increased needs of humans.

A- the effect on other natural resources is out of the scope since we are only dealing with fresh water in this argument

B- The total supply of fresh water has not diminished- I could not easily eliminate this answer choice so I negated it- " The total supply of freshwater has diminished in recent years" This sort of strengthens our argument so it can be eliminated.

D- Synthesizing water will have no effect on the quantity of fresh water available. If we negate this and we assume that yes synthesizing water will increase the quantity of fresh water available, it does not hurt our conclusion. Even if we had an increased supply of fresh water (through synthesizing), we may still need to place restrictions on that supply in order to meet the demands of man kind.

E-No previous attempt to increase fresh water supply available to humankind worked- this argument is failed because past performance should not be used as an indicator of future performance. Since you cant fix a flaw by using another flaw this can be eliminated easily.


C- is the correct answer- The freshwater supply will not increase sufficiently to meet the increased needs of humankind. If we negate this "The fresh water supply WILL increase to meet the demands of humankind then the argument is wrecked because it eradicates the need for water restrictions.

I have a question about answer choice D- If the answer choice was-

No attempts to synthesize water will have an appreciable effect on the quantity of water available to meet the freshwater needs of human being

and we negate the answer choice so it become:

Attempts at synthesizing water will have an appreciable effect on the quantity of water available to meet the freshwater needs of human beings- Would this answer choice be correct?

I am asking because I am wondering if my first flaw/assumption ( restriction on fresh water is the only way to deal with the increased demand) is correct.

[maryadkins]

Your analysis is perfect and the flaw you identified is correct. Well done!

As for your rephrase of (D), I like what you're getting at, but I think your actual rephrase is still a little off/confusing since "appreciable" just means noticeable. What you're trying to do is make (D) mean what (C) means. If we said that the argument is assuming that "no attempt to synthesize water will increase the amount of freshwater available SUFFICIENTLY TO MEET THE NEEDS of future populations," then yes, I'm with you, (D) would be required.

Good question! Keep it up!

[billyye125]

Hello.

I wonder if the following modification will make the choice valid: "No water conservation measure attempted an increase in the supply of freshwater" (which does not indicate if this measure is enough to meet the needs of human kind)?

When we say "a necessary assumption is an assumption, if negated, COMPLETELY destroys the argument," what do we mean by completely? For example, if the conclusion is "we will have water shortage," and the negation of a choice is "there is a method to supply some water," in this case is it COMPLETELY destroy the argument? I think we don't know if it COMPLETELY do that since it's possible that the supply is enough, but it is also possible that the supply is not enough.

Thank you!

[s.tofighbakhsh]

I also tripped up on this question. I selected D because I am paranoid about not considering possible alternatives that could destroy the argument (essentially I am paranoid about missing out on Defender Necessary Assumptions) and persuaded myself that negating D), Synthesizing Water WILL have an appreciable effect on Freshwater supply, destroys the argument by eliminating an alternative method for the water supply to increase. I realize now that this is a derivative of the ACTUAL assumption in the gap, which is that freshwater supply will not be proportionally going up (and that therefore we are assuming that no methods of increasing freshwater supply will work). But, I avoided C) because it seemed too Sufficient to guarantee the conclusion and matched precisely with my anticipated gap, and being painfully aware that this is a Necessary Assumption question, I didn't want to be entrapped by a Sufficient assumption decoy.

Now I could have meta-explained to myself that this sort of tricky LSAT-ery would be unlikely on the very first question in the set, but pretending this came directly in the hot zone, I'm still having trouble not giving into paranoia that I'll go chasing after the sufficient assumption I've affirmatively identified and miss the clever, unassuming necessary assumption that is totally critical but also out of left field. Is it MORE LIKELY that the answer choice to a necessary assumption question that is pretty damn close to the sufficient assumption that would plug the gap in the argument is the CORRECT answer, or that it is a DECOY? Getting stuck on my own nerves!

[ohthatpatrick]

There's a pretty simple answer to your understandable misery:
Make friends with the Negation Test

Suff Assump = which answer, if true, proves the conclusion
Nec Assump = which answer, if negated, most weakens the argument

If you were down to (C) and (D), and you negated each, you would be asking yourself,
"Which of these most weakens the argument?"
neg C) Freshwater supply will increase sufficiently to meet the needs of humankind
neg D) Some attempt to synthesize water will have an appreciable effect on freshwater supply