Q18 - Many physicists claim that quantum

[nanagyanewa]

Can someone please explain to me why C is the right answer? I eliminated down to A and E and I chose A. but it seems to me that C has a completely different structure that that in the stimulus. Thanks for any help

[aileenann]

Sure thing. Let's first think about why (C) looks like a good answer.

If we consider the original argument in very abstract terms, it basically says:

Many studiers of X say that Y should soon render X complete. However every theory of X so far has ultimately been rejected, so therefore we can ultimately expect that this one will be rejected to for failing to explain something or other.

(C) mirrors this very well once we also think about this in abstract terms:

In the past your sister has not done W therefore she will not do W.

It is not that the structure is the same but rather that the most fundamental reasoning of the logic is the same. That reasoning is that something that has happened (or not happened) in the past will happen (or continue not happening) in the future. Notice that the positive or negative framing of this issue doesn't matter - the reasoning is simply off a pattern expecting the status quo to remain going forward. This makes (C) a very good answer. However, since we're looking for the *best* answer we need to look at the others. In particular, I'll address (A) and (E) since those were the ones you found most interesting/convincing.

(A) is too broad and has a logical error not in the original. Specifically (A) reasons from plants to animals, which is not the same as what the original argument and (C) do. They only reason about the same thing in the past and in the future, not about two different kinds of things.

(E) commits the same error as (A) - it conflates the team itself with the team members. Therefore it doesn't match up very well with (C) for the very same reason.

Hope this helps. As always follow up if you have questions please!

[nanagyanewa]

Thanks, that helps!

[T.housman31]

This is flawed reasoning because of its committing a "time shift" error, right?

[ManhattanPrepLSAT1]

Absolutely. The argument in the stimulus commits flawed reasoning; the flaw being a temporal shift.

What's true now is not necessarily true in the future. What's true of the past won't necessarily be true now or in the future.

You nailed it...

[irene122]

Is it Ok if I understand E in this way?

It commits 2 flaws:
time shift ("has failed to live up" vs. "will not live up")
infer unwarrantly from individual to the whole ("each team member" vs. "the team")

since it commits one more flaw than the stimulus and this flaw does not mirror the one in the stimulus, E is incorrect.

Could any one please confirm/comment on the thought above? Thanks!

[cdjmarmon]

I still dont see how E is incorrect. Especially when the argument talks about how every theory in the history of mechanics has eventually failed then concludes one theory of mechanics (quantum physics) will not be the final.

Parallel with, every member on the team failed so the team will fail.

[timmydoeslsat]

Answer choice E does not mirror the flaw.

That is a part to whole flaw.

This argument is technically flawed, but is not a bad intuitive argument.

It, however, is not similar to part to whole.

We are told that every theory in history of physics has been unable to full explain. Therefore, this next new theory (quantum physics) will simply join the litany of others that failed to do so.

Notice how this argument is not going from a part to a whole. It is not making a claim about a whole from evidence about each of its parts.

[aznriceboi17]

I do think that C is the best answer available, but I was really thrown off by the fact that C has one object (Sarah) failing multiple times in the past, leading one to conclude that she will fail again in this upcoming attempt.

The provided example cites several other attempts by different objects (all physical theories that have come before quantum mechanics) that have all failed, leading one to conclude that the newcomer (quantum mechanics) will fail.

The fact that in one we have the same object failing multiple times, while in the other we have various other objects failing and now we consider the newcomer seemed like such a fundamental difference that I almost ruled out C as well. Did this bother anyone else?

[uhdang]

Forming an "abstract" reasoning structure is a very tricky thing. While I'm doing the question in timed condition, I sort of step back and try to see the general structure, and it feels like I am choosing an answer with uncertainty. When I try to review it, sometimes it gets more confusing or come up with some "abstract" structure I didn't think I used in actual problem-solving period.

But here is my take on this one after reviewing.

1) Expresses an opinion: "ultimately able to explain all" (A)
2) Brings in a general principle, or a broader statement, which involves “historical evidence” 3) conclude with disapproval of the first opinion: will not be the final theory. (~A)
Conclusion changes.

So it's like,

A ==[Broader principle with historical support] ==> ~A

*A isn't exactly the same. In the stimulus, "explaining all fundamental phenomena" becomes "not be the final theory." I don't know if I am allowed to do this, but I thought they were on the same track of thought, so considered them as similar-enough-to-be-signified-the-same (that's a weird word).

================== Answer Analysis ====================

A) Doesn’t look even remotely similar to the stimulus’ structure.

B) To be similar in any way, the second sentence should have followed the same action as the past action (fifth company should have marketed the new processing product).

C) “never won” brings in the “historical evidence” element to conclude contrasting point that was thought to be the opposite in the starting sentence just like in the stimulus.

A ==[Broader principle with historical support] ==> ~A
(Good player) ==[Never won a chess tournament] ==> (Will not win this tournament)

Looks close to the stimulus. (Correct)

D) While the stimulus goes over to apply general principle to a specific instance, this answer choice straight deals with specific instance all the way.

E) Generalizing individual’s quality to group did not happen in stimulus. And to be a bit closer to the stimulus, conclusion has to be different from the premise.