A simpler way to explain this (in my mind) as to why A is the correct option is to pay attention to the wording of conclusion of the stimulus: "types of medicine".
To produce (different) types of medicine, it would be necessary that there are substances of medicinal value contained in the plants not yet studied by scientists that differ from those there were already studied / discovered.
If your eyes kinda glazed over and you weren't even able to understand the right answer in the video, I highly recommend reading the explanation in writing beneath the video. It REALLY helped me acknowledge there was a metaphorical iceberg in the metaphorical water.
This question type is so frusturating because many of these questions my intuition is right, but I cannot for the life of me explain why they're right, they just feel right in my head. My head is doing some kind of processing but I cannot explain or write out the reasonings. Then there are the ones my inuition don't pick up and I feel lost.
Could anyone share with me how they would diagram answer choice D? I got a little thrown off by the "any" and then the "if", both of which are common sufficient condition indicators.
@OverheadHopefulStructure If "plant species indigenous to tropical rain forests" are studied by scientists, any substance of medicinal value contained in them will eventually be discovered. I don't recommend diagramming if it makes sense to you by just reading it
I saw D was the first one discussed in the video and was sad since I was sure it was A and then was pleasantly surprised to have my reasoning validated :D
Sharing my tactic here: I quickly eliminated D because it says, 'ANY substance... WILL eventually BE DISCOVERED.' However, based on the stimulus, it's not necessary for every substance to be discovered. Even if just some are discovered, the argument could still hold.
@BenPocheron This is a good heuristic. However, I would caution that the correct answer to a SA question can sometimes be sufficient to make the argument valid. In other words, the correct answer to a SA question is not always a weak answer - the correct answer can also go far beyond what is strictly necessary (and it will be the correct answer, assuming all the other choices are incorrect).
@AudreyGilmour Thank you very much for your comment. However, I don’t think I stated any reasoning about strong or weak answers for this question.
To rephrase my point: imagine you are the author of the argument, say, a scientist, and you are presenting the argument (the stimulus) to an audience. Would you, as the scientist, have in the back of your mind the assumption that “any substance of medicinal value (...) will eventually be discovered (...)”? Of course not, that would be far beyond what the scientist intended. Such an assumption goes well outside the scope of the argument. Again, if you negate D, the argument still holds perfectly.
#help Can anyone shed some light on why prescriptive or descriptive answer choices are bad in NA questions? Or just which module JY covers this in? I may have missed it.
@fmarshal90 I believe that if the the conclusion is prescriptive, a necessary assumption must be that whatever act, phenomena, etc... being prescribed is worthwhile. Otherwise, why would it need to be done?
And for descriptive, if the conclusion is descriptive, the NA is also likely descriptive, and definitely not prescriptive. If we're describing why a plant is definitely yellow, its NOT a necessary assumption that it should be that was. It just is.
I kind of struggled to wrap my head around this but I think I figured it out. I had initially predicted the assumption that "hey, what if those other plants don't have the substances?". Despite it being very likely, I did think it was an important assumption that was somewhat necessary for the conclusion. Now my issue was with why does it have to differ from existing meds/substances already discovered? The way I was able to understand this, I looked back at the context. NOTICE that many important types of medicine have already been developed. Our conclusion is that MORE types of medicines will never be developed without the rainforests. SO this means that to develop those important medicines, we MUST discover different substances from those that have already been found to develop meds. This made it easier for me to understand. If negated, it would basically say any new discovered plants would just have the same substances as the existing meds that have already been discovered. This causes the conclusion to crash because NOTE the substances we would find have already made medication. Hope this helps someone
WHEWWWW I see why B, C, D, and E are wrong but my gosh, I cant imagine being able to figure out why A is right -- bc it feels like ther are other (more important) ncessary assumptions than A that are skipped, and like JY pointed out - that can easily seem similar to other ansers.
I think it would be true to say that its not that A is the ONLY necessary assumption for this argument to hold, but that it is ONE of the necessary assumptions the argument needs to hold. The NA that it isnt possible to find these medicines anywhere other than this rain forst still is required, its just that its not an option
Is this accurate?
Either way Im gonna follow JYs advise and starred this question and will come back and try to work it when Im done this unit
Yes that is accurate. The question is simply asking you to pick which out of the options is a necessary assumption. It is not suggesting that there is only ONE. There are many necessary assumptions for almost any argument. Another necessary assumption that the argument commits to is that the plants which MAY be developed into medicine, WOULD be useful for development into medicine (...what if it turned out that these plants which are "likely" to be medicinal are in fact NOT... then we could not conclude that "if the tropical rainforest is not preserved, important types of medicine will never be developed"). The necessary assumption can range to be even more general and can range to be assumptions that are perfectly reasonable. There are, in a sense, an infinite amount of necessary assumptions for any argument. When picking an answer, we are always only ever looking for ONE of them. The thing that will distinguish the incorrect answer choices is that they are decidedly NOT necessary assumptions.
#help. Doesn't answer D, if negated, destroy the argument? "No substances of medicinal value contained in rain forest plant species will eventually be discovered if those species are studied." Essentially saying that even if the species are studied, we won't get medicinal value from them. Which basically renders the argument null bc if we don't have the rain forests, who cares because the plants wouldn't have any medicinal value anyways?
I'm not sure if I'm negating the answer wrong or if I'm just misunderstanding it. But I definitely am lost. #help
I'm pretty sure 'any' can be interpreted as 'all', in which case the negation would be 'not all'. and so it doesn't destroy the argument because we don't need ALL substances of medicinal value to be discovered.
Why does offering a sub-premise to support an existing premise from the argument strengthen the argument itself, since we already take all existing premises to be true?
An analogy:
Argument 1: Riding motorcycles is dangerous. People should not do dangerous things. Therefore, people should not ride motorcycles.
Argument 2: Riding motorcycles is dangerous because 20% of people who ride them will get into a serious car crash. People should not do dangerous things. Therefore, people should not ride motorcycles.
Aren't both arguments the same strength since they're both valid? Or is argument 2 stronger than argument 1 since it has an additional sub-premise that supports its first premise?
Strength and validity are different concepts. Strength relates to the quality of evidence/support, while validity relates to argument form/structure. An argument can be valid in form yet weak in support. The second one would be stronger since it provides support to the claim that motorcycles are dangerous. An even stronger version of the argument might provide support for the claim that people should not do dangerous things.
If we refer back to the spectrum of support, the strength of an argument depends on the support structure. Arguments that are airtight (super strong, must be true) are valid. So, I think of validity as a type of strength (the strongest type). I don't think an argument can be valid while having weak support?
I guess it depends on your definitions of strong and weak. With strength just meaning the strength of support/form, yes, all valid arguments are strong. But I think the word strength is used in a much more inclusive way in the context of these lessons. He also talks about the spectrum of reasonableness, which looks at the spectrum of support alongside assumptions and says the fewer assumptions you have to make for a conclusion to follow, the stronger it is. In your motorcycle argument, the first formulation assumes that motorcycles are dangerous because you are likely to get in an accident or get injured. In the second formulation, you don't have to make that assumption because you provide evidence as to why they are dangerous. If you include reasonableness in your assessment of strength, it makes more sense why some valid arguments are "stronger" than others. For an example of an argument that could be considered valid in form but makes unreasonable assumptions, look at lesson 9 from the flaw section.
Sorry, that wasn't very clear. I am talking about lesson 9 from the flaw or descriptive weakening section, "democracy and self-interest". There might be better examples, but I did this one recently.
#help I understand why answer choice D does not work. However, if we switched the sufficient and necessary conditions in D, why wouldn't it work? JY said, "Even if we flipped the bridge around, it’s still not necessary. Rather, what is necessary is that if those plant species are not studied, then those substances of medical value will not be discovered." Doesn't that match the necessary condition of the revised D?
I eliminated E because I didn't think it was really an assumption and rather just restated the argument, but are all prescriptive answer choices always wrong on NA questions?
#feedback This is silly feedback, but in the written explanation there is a typo in the line: "I say 'kind of' because even if we flipped th bridge around, it’s still not necessary." ("th" should be "the")
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87 comments
A simpler way to explain this (in my mind) as to why A is the correct option is to pay attention to the wording of conclusion of the stimulus: "types of medicine".
To produce (different) types of medicine, it would be necessary that there are substances of medicinal value contained in the plants not yet studied by scientists that differ from those there were already studied / discovered.
im gonna freak out
Is it fair to assume that I can automatically eleminate answers that are either irrelevant or that actually weaken the argument (in NA questions) ?
If your eyes kinda glazed over and you weren't even able to understand the right answer in the video, I highly recommend reading the explanation in writing beneath the video. It REALLY helped me acknowledge there was a metaphorical iceberg in the metaphorical water.
I would definitely get this question wrong
Is it just me... or is it getting harder at figuring out what the underlying assumptions are in these arguments?
@cwferrari I agree
When he is explaining choice E, would anyone be able to let me know the lesson where he discusses descriptive vs prescriptive words
@Jake. Wondering this as well, he started using these terms in lessons without a dedicated lesson in my study plan
This question type is so frusturating because many of these questions my intuition is right, but I cannot for the life of me explain why they're right, they just feel right in my head. My head is doing some kind of processing but I cannot explain or write out the reasonings. Then there are the ones my inuition don't pick up and I feel lost.
That answer choice felt like it was a paraphrase from the gist of the argument which i guess makes sense? IDK maybe I am having a stroke LOL
@edward.ratkoczy same this lesson is gonna put me in the er
He lowkey made it way more complicated than it needs to be...
@mrrobotjeremy yeah, I try to retain what will actually help me score better on this test.
Could anyone share with me how they would diagram answer choice D? I got a little thrown off by the "any" and then the "if", both of which are common sufficient condition indicators.
@OverheadHopefulStructure If "plant species indigenous to tropical rain forests" are studied by scientists, any substance of medicinal value contained in them will eventually be discovered. I don't recommend diagramming if it makes sense to you by just reading it
I saw D was the first one discussed in the video and was sad since I was sure it was A and then was pleasantly surprised to have my reasoning validated :D
Thank you for saying "from whom" when referring to plants <
Sharing my tactic here: I quickly eliminated D because it says, 'ANY substance... WILL eventually BE DISCOVERED.' However, based on the stimulus, it's not necessary for every substance to be discovered. Even if just some are discovered, the argument could still hold.
@BenPocheron This is a good heuristic. However, I would caution that the correct answer to a SA question can sometimes be sufficient to make the argument valid. In other words, the correct answer to a SA question is not always a weak answer - the correct answer can also go far beyond what is strictly necessary (and it will be the correct answer, assuming all the other choices are incorrect).
@AudreyGilmour *Sorry, I mean a NA question, not SA!
@AudreyGilmour Thank you very much for your comment. However, I don’t think I stated any reasoning about strong or weak answers for this question.
To rephrase my point: imagine you are the author of the argument, say, a scientist, and you are presenting the argument (the stimulus) to an audience. Would you, as the scientist, have in the back of your mind the assumption that “any substance of medicinal value (...) will eventually be discovered (...)”? Of course not, that would be far beyond what the scientist intended. Such an assumption goes well outside the scope of the argument. Again, if you negate D, the argument still holds perfectly.
#help Can anyone shed some light on why prescriptive or descriptive answer choices are bad in NA questions? Or just which module JY covers this in? I may have missed it.
@fmarshal90 I believe that if the the conclusion is prescriptive, a necessary assumption must be that whatever act, phenomena, etc... being prescribed is worthwhile. Otherwise, why would it need to be done?
And for descriptive, if the conclusion is descriptive, the NA is also likely descriptive, and definitely not prescriptive. If we're describing why a plant is definitely yellow, its NOT a necessary assumption that it should be that was. It just is.
I kind of struggled to wrap my head around this but I think I figured it out. I had initially predicted the assumption that "hey, what if those other plants don't have the substances?". Despite it being very likely, I did think it was an important assumption that was somewhat necessary for the conclusion. Now my issue was with why does it have to differ from existing meds/substances already discovered? The way I was able to understand this, I looked back at the context. NOTICE that many important types of medicine have already been developed. Our conclusion is that MORE types of medicines will never be developed without the rainforests. SO this means that to develop those important medicines, we MUST discover different substances from those that have already been found to develop meds. This made it easier for me to understand. If negated, it would basically say any new discovered plants would just have the same substances as the existing meds that have already been discovered. This causes the conclusion to crash because NOTE the substances we would find have already made medication. Hope this helps someone
WHEWWWW I see why B, C, D, and E are wrong but my gosh, I cant imagine being able to figure out why A is right -- bc it feels like ther are other (more important) ncessary assumptions than A that are skipped, and like JY pointed out - that can easily seem similar to other ansers.
I think it would be true to say that its not that A is the ONLY necessary assumption for this argument to hold, but that it is ONE of the necessary assumptions the argument needs to hold. The NA that it isnt possible to find these medicines anywhere other than this rain forst still is required, its just that its not an option
Is this accurate?
Either way Im gonna follow JYs advise and starred this question and will come back and try to work it when Im done this unit
Yes that is accurate. The question is simply asking you to pick which out of the options is a necessary assumption. It is not suggesting that there is only ONE. There are many necessary assumptions for almost any argument. Another necessary assumption that the argument commits to is that the plants which MAY be developed into medicine, WOULD be useful for development into medicine (...what if it turned out that these plants which are "likely" to be medicinal are in fact NOT... then we could not conclude that "if the tropical rainforest is not preserved, important types of medicine will never be developed"). The necessary assumption can range to be even more general and can range to be assumptions that are perfectly reasonable. There are, in a sense, an infinite amount of necessary assumptions for any argument. When picking an answer, we are always only ever looking for ONE of them. The thing that will distinguish the incorrect answer choices is that they are decidedly NOT necessary assumptions.
#help. Doesn't answer D, if negated, destroy the argument? "No substances of medicinal value contained in rain forest plant species will eventually be discovered if those species are studied." Essentially saying that even if the species are studied, we won't get medicinal value from them. Which basically renders the argument null bc if we don't have the rain forests, who cares because the plants wouldn't have any medicinal value anyways?
I'm not sure if I'm negating the answer wrong or if I'm just misunderstanding it. But I definitely am lost. #help
I'm pretty sure 'any' can be interpreted as 'all', in which case the negation would be 'not all'. and so it doesn't destroy the argument because we don't need ALL substances of medicinal value to be discovered.
When JY gets to your answer choices and says “oooookayyyy…” yk you’re cooked
#help
Why does offering a sub-premise to support an existing premise from the argument strengthen the argument itself, since we already take all existing premises to be true?
An analogy:
Argument 1: Riding motorcycles is dangerous. People should not do dangerous things. Therefore, people should not ride motorcycles.
Argument 2: Riding motorcycles is dangerous because 20% of people who ride them will get into a serious car crash. People should not do dangerous things. Therefore, people should not ride motorcycles.
Aren't both arguments the same strength since they're both valid? Or is argument 2 stronger than argument 1 since it has an additional sub-premise that supports its first premise?
Strength and validity are different concepts. Strength relates to the quality of evidence/support, while validity relates to argument form/structure. An argument can be valid in form yet weak in support. The second one would be stronger since it provides support to the claim that motorcycles are dangerous. An even stronger version of the argument might provide support for the claim that people should not do dangerous things.
If we refer back to the spectrum of support, the strength of an argument depends on the support structure. Arguments that are airtight (super strong, must be true) are valid. So, I think of validity as a type of strength (the strongest type). I don't think an argument can be valid while having weak support?
I guess it depends on your definitions of strong and weak. With strength just meaning the strength of support/form, yes, all valid arguments are strong. But I think the word strength is used in a much more inclusive way in the context of these lessons. He also talks about the spectrum of reasonableness, which looks at the spectrum of support alongside assumptions and says the fewer assumptions you have to make for a conclusion to follow, the stronger it is. In your motorcycle argument, the first formulation assumes that motorcycles are dangerous because you are likely to get in an accident or get injured. In the second formulation, you don't have to make that assumption because you provide evidence as to why they are dangerous. If you include reasonableness in your assessment of strength, it makes more sense why some valid arguments are "stronger" than others. For an example of an argument that could be considered valid in form but makes unreasonable assumptions, look at lesson 9 from the flaw section.
Hi Chloe, thanks! Are you referring to "some before some"?
Sorry, that wasn't very clear. I am talking about lesson 9 from the flaw or descriptive weakening section, "democracy and self-interest". There might be better examples, but I did this one recently.
Oh, thank you! Haven't gotten there yet but will check it out
#help I understand why answer choice D does not work. However, if we switched the sufficient and necessary conditions in D, why wouldn't it work? JY said, "Even if we flipped the bridge around, it’s still not necessary. Rather, what is necessary is that if those plant species are not studied, then those substances of medical value will not be discovered." Doesn't that match the necessary condition of the revised D?
Is there a baseline for when we should use/ or eliminate prescriptive answer choices for certain answer types?
Same for descriptive answer choices
When he reads the answer choices, I understand it better LOL
I eliminated E because I didn't think it was really an assumption and rather just restated the argument, but are all prescriptive answer choices always wrong on NA questions?
#feedback This is silly feedback, but in the written explanation there is a typo in the line: "I say 'kind of' because even if we flipped th bridge around, it’s still not necessary." ("th" should be "the")
Thanks, fixed!