PT 15 Section 3_Q13 Forum

[existence1943]

Hello guys,

I am very confused why D is wrong.

Here is my break down of the logic structure of the stimulus:
==A (a category) has C (certain traits/properties)
==B (an individual) belongs to A (category)
===> Thus, B also has C (certain traits/properties)

Admittedly, answer A is correct. The reason I passed A when I did the test was that grass is not always green, there could be purple or brown live grass. But I guess the hidden consensus here does not consider these possibilities. On condition of that, I can accept A as the correct answer. However, D is equally correct to me. Below is my breakdown of answer D:

==Movies directed by Rainer (a category) is seen by Dierdre (A property);
==Ali:... is a movies directed by Rainer
===> Thus, Ali:... has the property of the movies directed by Rainer. In another word, Ali: ... must be seen by Dierdre.

Is there anything missing in my breakdown of the argument?

Thx in advance!

[Jeffort]

The reasoning of the stimulus includes the assumption that thing B (alligators) belongs to category A (reptiles) in order to link the category definition premise to the conclusion.

The reasoning in (A) also includes the assumption that thing B (grass) belongs to category A (green plants) in order to link the premise to the conclusion. While the assumption in the stimulus that alligators are reptiles is always true in life, your observation that grass is not always green in real life is correct, but doesn't change the reasoning structure of the arguments.

(D) is incorrect because its reasoning doesn't include, need or depend up an unstated assumption. The premise at the end states explicitly that the film is one that was directed by Fassbinder.

Although AC (A) is slightly different than the argument in the stimulus because the assumption that grass is a green plant could be false, whereas the assumption in the stimulus must be true in real life, (A) is the only answer choice with the same reasoning structure as the stimulus including an assumption that the thing in the conclusion belongs to the group defined in the premise.

On some rare occasions, the method of reasoning and all features of the correct answer choice argument for parallel reasoning questions aren't always 100% the same as the argument in the stimulus.

Make sense?

[existence1943]

The reasoning of the stimulus includes the assumption that thing B (alligators) belongs to category A (reptiles) in order to link the category definition premise to the conclusion.

The reasoning in (A) also includes the assumption that thing B (grass) belongs to category A (green plants) in order to link the premise to the conclusion. While the assumption in the stimulus that alligators are reptiles is always true in life, your observation that grass is not always green in real life is correct, but doesn't change the reasoning structure of the arguments.

(D) is incorrect because its reasoning doesn't include, need or depend up an unstated assumption. The premise at the end states explicitly that the film is one that was directed by Fassbinder.

Although AC (A) is slightly different than the argument in the stimulus because the assumption that grass is a green plant could be false, whereas the assumption in the stimulus must be true in real life, (A) is the only answer choice with the same reasoning structure as the stimulus including an assumption that the thing in the conclusion belongs to the group defined in the premise.

On some rare occasions, the method of reasoning and all features of the correct answer choice argument for parallel reasoning questions aren't always 100% the same as the argument in the stimulus.

Make sense?

Hey, thanks for the explanation. Yeah, it makes sense. But I am not quite sure if this LSAT question is a good one then, 'cus it's too ambiguous. For most LSAT parallel question I've come across, whether something is stated explicitly or not is too minor to distinct a reasoning structure from another.

I don't think I can get it correct in test settings.