Q10 - Science journalist: Europa, a moon

[irini101]

What does B mean? I understand the flaw in the stimulus is conditional reasoning mistaken reversal, but shouldn't the correct answer says sth like "liquid water is not sufficient for the presence of life"? Why B adds some additional necessary conditions?

I must have misread B or missed something, could any one help?

Thanks in advance!

[noah]

This is a classic flaw question!

The conclusion is that it's likely there's life (yes, "at least primitive life") on Europa. Why? Because there's probably water there, and water is needed for life as we know it to evolve.

What's the problem with this argument? I agree that it's a good sign that there's water - now there's a chance for life to have evolved - but what about the temperature, atmosphere, level of gravity, etc.? Aren't there other factors that are needed for life to evolve? This is what (B) gets at. When an argument is confusing necessary and sufficient conditions, one way to point out this flaw is to simply say "Hey, you're confusing necessary and sufficient!" while the other way, as (B) does, is to point out the other possibilities.

For example, take this argument: Jon needs money to get to Vegas. He got money, so he surely has made it to Vegas. Money is necessary, but not sufficient - he also needs a mode of transportation that doesn't break down! And, instead of saying anything about mistaken reversal, you can say "you're failing to address the possibility that there are conditions necessary for getting to Vegas other than having money!"

I love the wrong answers on this question - really tricky stuff!

(A) is tempting as it addresses the condition about life and water, however the second part is off. It should say something like "If a condition is necessary, then it's sufficient." Instead it tells us that life couldn't have evolved elsewhere without water - but we already knew that! Premise booster.

(C) is tricky - it's playing on a misreading of the conclusion. The conclusion is that it's likely that life evolved on Europa. If you misread and thought this is about life being present on Europa, then this is tempting, because you might have thought "Hey, maybe life landed there in a spaceship!"

(D) is about a different argument - one in which there isn't water on Europa. We don't care if life might have occurred without water since we have water!

(E) is doubting the premise - premise de-booster! We must accept that the data strongly suggests there's water. The issue at hand is whether we can draw the given conclusion (also something that's "likely") from this strongly-suggested data.

I hope that clears it up.

[shaynfernandez]

The conclusion is not saying that life evolved, it is saying it is Likely that life evolved. I understand why. B is correct but not why C is wrong. Just because you concluded that " it is likely I got this question right" does not make your conclusion correct.

[noah]

The conclusion is not saying that life evolved, it is saying it is Likely that life evolved. I understand why. B is correct but not why C is wrong. Just because you concluded that " it is likely I got this question right" does not make your conclusion correct.

Thanks for pointing out that my original explanation for (C) left out the "likely" bit. I just fixed that.

To explain it in a different way, the argument is all about whether the fact that the presence of water, and the fact that water is necessary for life to evolve means that we can conclude that it's likely that some life evolved on Europa.

(C) is about the connection between the presence of life somewhere and that life having evolved there. The presence of life is out of scope -- we're only interested in whether life has ever evolved somewhere. We don't know if life is present on Europa. This answer doesn't point out an issue in the connection between the given premises and the conclusion.

Tell me if it's still unclear, and, if so, what makes (C) attractive.

[redcobra21]

Thanks for the great response Noah. This is probably a stupid question, but I'm still having some trouble understanding this question and was wondering if you could answer a question of mine if you had a chance.

It's extremely clear that the flaw is a mistaken reversal in that the argument is Life --> PW, PW, so L. I'm confused though at how (B) address the issue of a mistaken reversal.

To take a clear example in the strategy guide, let's say we have something like: If Sally lives in Boston, then she lives in Massachusetts. If we applied the flaw in this question, we could say that we know she lives (or is likely) to live in Massachusetts, so we know she lives in Boston.

How would (B) address that though? Then you'd have something like: "argument is vulnerable on the grounds that it fails to address the possibility that there are conditions necessary for living in Boston in addition to living in Massachusetts." I'm having a hard time how that specifically addresses a flaw of mistaken reversal.

Hopefully that made sense. Thanks for your help!!

[ptewarie]

Thanks for the great response Noah. This is probably a stupid question, but I'm still having some trouble understanding this question and was wondering if you could answer a question of mine if you had a chance.

It's extremely clear that the flaw is a mistaken reversal in that the argument is Life --> PW, PW, so L. I'm confused though at how (B) address the issue of a mistaken reversal.

To take a clear example in the strategy guide, let's say we have something like: If Sally lives in Boston, then she lives in Massachusetts. If we applied the flaw in this question, we could say that we know she lives (or is likely) to live in Massachusetts, so we know she lives in Boston.

How would (B) address that though? Then you'd have something like: "argument is vulnerable on the grounds that it fails to address the possibility that there are conditions necessary for living in Boston in addition to living in Massachusetts." I'm having a hard time how that specifically addresses a flaw of mistaken reversal.

Hopefully that made sense. Thanks for your help!!

Awesome question. Take a look at this:

The author goes from saying that:
If Life--> Liquid
to
If liquid --> Life

As you properly inferred, this is a mistaken flaw of "affirming the consequent" or assuming that what is necessary can also be sufficient. Those answer choices are not given to us, however.
Rather, we need to dig a bit deeper and find the answer choice that say the same thing, albeit in different ways.

Answer choice B, says "fails to address possibility thaat there are conditions necessary for life in addition to presence of water"
In other words, this states that the author mistakenly inferred if life then liquid to mean Life IF and ONLY IF liquid.

This hit it on the nail. For if the author assumed
Life IF AND ONLY IF liquid then he could properly infer that:

If Life then liquid
If Liquid then Life.

The latter of which, the author concluded.



Just as a side note.
When an author makes an If-then statement, the author does NOT regularly assume that there can be no additional necessary conditions for the sufficient condition.

In other words,

If Boston-> Mass

does NOT preclude

If Boston--> USA

OR

If Boston-> North America

Boston is sufficient to trigger ALL those necessary portions.
However, if the author says

If Boston-> Mass

THUS

Mass-> Boston

the author MISTAKENLY rules out all other necessary possibilities that could have been triggered by boston( north america, USA, East Coast..etc.)
This is an unwarranted assumption, to the exeption of when the stimulus specifically rules out other necessary portions as in when it says "IF AND ONLY IF". If it doesn't that the author is imaging "if and only if"( and thus ruling out other necessary portions) without being warranted in doing so.

[jenniferreisig]

Is B correct because it attacks the necessary condition in the stimulus?

[maria487]

Can someone please further elaborate why (D) is wrong?

[ohthatpatrick]

Sure. When you see Flaw answer choices start with ...

overlooks/ignores the possibility
neglects/fails to consider

... just ask yourself, "If true, would this weaken the argument?"

Let's try it with (D):
"Hey, author, you know there could be unfamiliar forms of life that have evolved without the presence of liquid water."

Does this Weaken the author's argument?

Author:
I'm pretty sure I acknowledged the possibility of weird, water-less life by saying "Life as we know it requires water." If I weren't allowing for that possibility, I would have just said "Life requires the presence of water."

Also, what does that have to do with my conclusion? I'm trying to establish that it's likely that there is primitive life on Europa.

Are you saying, "It's unlikely that there's primitive life on Europa, because there could be weird forms of life that don't need water?" That objection doesn't make any sense.

====

Sorry, that author was a little sassy. That's how I hear these LSAT blowhards and high-paid lawyers.

[mswang7]

I was attracted to D because I thought it addressed another possible form of life. In the argument it states "life as we know it" and D says "unfamiliar forms of life." Is this still the incorrect answer because B is the better answer? Or am I mis-interpreting something?

[Laura Damone]

Hi there!

Like Patrick said in the previous post, a flaw answer that begins with "overlooks the possibility" or "fails to consider" needs to introduce something that would weaken the argument in the stimulus.

Say, for example, the stimulus made this argument:

The human eye perceives blue light more easily than other-colored light. This explains why the sky appears blue to humans.

Does the argument actively consider the possibility that blue light scatters through our atmosphere differently than other color light, which may impact the way it is perceived by humans? No it doesn't. And is the argument flawed because it overlooks this possibility? Absolutely. Why? Because anything else that might cause us to perceive the sky as blue would mess up the argument.

What about this: Does this argument actively consider the possibility that rainbows are a gift to humanity given by leprechauns? No again. But is the argument flawed because it overlooks this possibility? Not at all. Why? Because leprechauns giving us rainbows doesn't mess up the argument.

So now let's go back to the question at hand. The argument breaks down like this:
Data suggests Europa has water. Life as we know it requires water. Therefore Europa probably has some life.

D accuses the argument of overlooking the possibility that some life doesn't require water. In other words, it's attacking that second premise. Right away, this should raise a red flag. If the LSAT gives you a premise, accept it as true. Flaw answers and Weaken answers won't reverse course and say "But what if that premise isn't true."

Instead, Flaw and Weaken answers will attack the logic of the argument. You were smart to be thinking about alternatives as a way to attack logic. That's something the LSAT does all the time, so good work there! If you need to weaken an argument that makes a recommendation, proposes an explanation, or makes a cause and effect claim, it's highly likely that the right answer will acknowledge some sort of alternative.

But this particular argument doesn't do any of those things. It makes a prediction based on some facts. That's not the kind of argument where alternatives are likely to be important.

So, does the alternative presented in D weaken this argument? Nope. Because so what if life can exist without water? Does that make our conclusion less likely? Is it now less likely that Europa has life? Not at all. If anything it's more likely, so overlooking this possibility didn't weaken the argument.

Hope this helps!