to the top

#21 - When the supply of a given resource dwindles

LSAT Leader
Posts: 76
Joined: Mon Apr 11, 2016 11:35 pm
Points: 2


I chose ans choice B simply because i am confused as to what is meant by "biological requirements" of clean air and clean water?


- Arindom
Emily Haney-Caron
PowerScore Staff
PowerScore Staff
Posts: 577
Joined: Thu Jan 12, 2012 11:26 am
Points: 418

Hi Arindom,

By "biological requirements" it basically means "physically necessary for life to be sustained." In contrast to flint for arrowheads, for example, animals and plants all need clean water and air to survive; no matter what technology we come up with, if we run out of those resources, we're in trouble. Does that help explain it?
LSAT Apprentice
Posts: 10
Joined: Sat Aug 20, 2016 6:51 pm
Points: 3

Hello, I also chose B for this question. I see how E is the correct answer but doesn't B also undermine the argument because if we have less mules today than 100 years ago then we don't have "more than adequate supply" if they have been decreasing. I am assuming E undermines the argument more which is why it is correct, but I just wanted to clarify and see if B somewhat undermines it as well. Thank you.
Claire Horan
PowerScore Staff
PowerScore Staff
Posts: 310
Joined: Mon Apr 18, 2016 3:03 pm
Points: 237

Answer choice (B) does not undermine the argument at all. Rather, it is completely consistent with the argument. If mules are an example of a resource that dwindled, alternative technologies developed (engines) to allow us to use other resources (metal, etc.) to transport ourselves and our stuff. There is still some demand for mules, but there is "more than adequate supply" to meet the demand because the demand has decreased so much. The total number of mules may have decreased, but there is no deficit of mules as a resource.
LSAT Apprentice
Posts: 8
Joined: Fri Feb 10, 2017 12:20 pm
Points: 8

Can you please explain why E is correct? It still is not making 100% sense to me... If the conclusion states "we can never run out of important resources" , and this is a Weaken Q; how could "substances like clean air and water are unaffected by technological change" be a weakening statement?
Jon Denning
PowerScore Staff
PowerScore Staff
Posts: 854
Joined: Mon Apr 11, 2011 4:36 pm
Points: 1,118

Hi gmosquera - thanks for the question!

Let's start with the argument itself here, particularly the conclusion, so we're clear on exactly what we're trying to weaken.

The final sentence gives us the main point: because new tech constantly replaces old tech, we can never run out of important natural resources. Why does the author think important natural resources are essentially inexhaustible due to new technology?
Because running low on the supply of some resource leads to alternative technologies arising that allow us to use different resources instead. This in turn leads to a lower demand for the original resource, so even though it's in short supply, the reduced demand can be satisfied.

So how does (E) weaken that idea of new technology allowing us to transition from a threatened resource to a new one? By telling us that the demand for some resources, like clean air and water, will remain no matter what due to our biological need for them. In other words, even with new technology, the need for those particular resources will remain the same...thus if we threaten their supply we could indeed be faced with running out.

Compare the examples of air and water in (E) with the three examples in the stimulus, arrowhead flint, schooner mast wood, and good mules. Each of the stimulus examples has been supplanted by tech—bullets, steel, and engines, respectively—so they serve the author's point. They're also unnecessary in the sense that we can either do without them or find a replacement elsewhere. But the two examples in (E), where we're told that new technology can't affect them (i.e. won't allow us to replace them or avoid their use), tell a different story: suddenly we have resources from which new technology can't provide escape or relief. Suddenly we have the potential to reduce supply without being able to look elsewhere for a substitute. So I see it as the difference of technology being able to provide substitutes/alternative to important but avoidable natural resources (stimulus/argument) versus an inherent need for particular resources that technology can't supplant.

Put another way: we don't have an inherent need for arrowheads or ship masts or mules to survive. They were useful once, but not genuinely required as-is for life to carry on. So if any start running low, we'll simply do without or find a substitute (that's where the tech comes in). But if you're given things that technology can't help us avoid or replace, like air and water, and told those things are biological requirements (so life depends on them), then suddenly we have a big problem if supply starts to dwindle. We can never fully reduce/remove demand since they're biological requirements, and we can never truly replace them with tech since, from (E), they're unaffected by technological change.

And that's why (E) weakens this argument.

I hope that helps!
Jon Denning
PowerScore Test Preparation

Follow me on Twitter at
My LSAT Articles:
LSAT Novice
Posts: 4
Joined: Sun Oct 14, 2018 10:30 pm
Points: 4


I would like clarification if my line of reasoning is correct in getting the right answer choice. After looking at the question again, I realized I eliminated answers A through D, and only chose E because it seemed the most plausible. With my second look, does this sound accurate?

(Cause) New technologies constantly replace old ones -> (Effect) We can never run out of natural resources.

One of the methods that the LRB says to weaken a conclusion is to find when a cause occurs, show that the effect does not occur. My thinking is, even if new technologies constantly replace old ones, we can still run out of oxygen and water.
Rachael Wilkenfeld
PowerScore Staff
PowerScore Staff
Posts: 138
Joined: Thu Dec 15, 2011 5:55 am
Points: 134

Hi Psalom,

That's a really good way to think about this stimulus. The key is the assumption that when a resource declines, an alternative technology will come up to replace it. Since answer choice (E) describes resources that cannot be replaced, it weakens the argument that there can be a replacement.

Great job!