Wait, can someone explain why the phrase "the amount of aesthetic pleasure a diamond provides is relevant to the value it commands" doesn't justify the conclusion?
I feel like it goes hand-in-hand with the premise and conclusion? The conclusion was that they should be deemed of equal value, and if they both give the same amount of aesthetic pleasure, why would the necessary assumption not justify the conclusion?
@nycxchi aesthetic value may be "relevant to the value it commands"
but it does not tell you enough to say "both should be deemed of equal value"
aesthetic value could, for example be relevant to a very small degree, but there could be some much more important factor to the value a diamond command commands.
it leaves the door open for a possibility such as "the diamond looks good, sure, and that matters a little bit, but the value of knowing a diamond is real matters much more"
in that world, "both should be deemed of equal value" would be false
@ZachistheLawyerinCharge You misunderstand. He is saying winning 5 MVPS isn't necessary for being one the best players of all time. You could have 4, 3, 2, 10 MVP awards. Who cares if its 5. Who cares if its any. It's not necessary.
@SimonArmendariz I didnt say anything about being one of the best of all time. You misunderstand what I wrote. I said it's safe to assume someone knows how to dribble a basketball if they've won 5 mvps.
@ZachistheLawyerinCharge Ah. I mean that's true that that is a reasonable assumption, but those conditions were never put together like that in the previous lesson's example.
Just to confirm.... is this rule sufficient and necessary? "Rule: the value of a diamond should derive solely from the aesthetic pleasure it provides."
Or, in the example, is it only the rule "the amount of aesthetic pleasure that a diamond provides is relevant to the value that it commands" that is necessary (but not sufficient)?
@e.wimoine To be sufficient it has to strengthen the conclusion to a degree that it is believable and possibly valid. To be necessary it just has to be grounds for which something can be true.
I’m in a fantasy football league with friends. Quick refresher: you draft real players, set a lineup, and your team scores based on how those players do in real games.
This week Friend 1 was playing Friend 2. The score was 120 to 135. Friend 1 was down 15, and here is the kicker: he left his quarterback slot empty. Friend 2’s whole roster had already played, so 135 was his final score.
I told Friend 1, “If you want any chance to win, you need to start a QB.” Friend 2 jumped in and said, “Even if he adds a QB, that does not mean he will get 16 or more points.” I said, “Right, it is not a guaranteed win. But without a QB, there is zero chance.” That is the point. It is a necessary condition. A QB does not ensure victory, but no QB ensures defeat.
Shoutout to 7Sage. LSAT necessary assumptions can even help you talk trash with logic.
I don't understand how the jewels sentence is not necessary but it is sufficient. I get that it is not as narrowly tailored, but diamonds still fit into the category of jewels so that sentence still applies to them. I feel like the way this concept was explained went completely over my head. I understood everything until that point where it was sufficient but not necessary yet still applicable to diamonds because diamonds are jewels. Unless my problem is that I made the assumption that all diamonds are jewels.
@LSATWarrior My take is that - being able to swap out the word proves it is unnecessary. Necessary means that without that rule, the argument breaks. So you can actually say that about the sufficient answer. You can essentially negate that argument and still get a logical argument. "The value of a jewel should NOT derive solely from the aesthetic pleasure it provides". The argument can still hold true in this case still.
So, even though necessary conditions generally cast a wider 'net' (as the large circle with several sufficient conditions inside it) it actually needs to be more specific -- tailored -- to the argument than a sufficient assumption?
Yeah because if you falsify a sufficient assumption it does not completely destroy an argument. This is because the argument does not need the sufficient assumption in order to stand.
On the diamond question: another necessary assumption is that diamonds have any value at all. It is necessary for a diamond to have any kind of value in order for its value to be derived from aesthetic pleasure, yet it having any value at all is not sufficient for that argument we're referencing to be true. I think if we were to deny this necessary assumption, it would hurt the diamond-value argument even more than the example given here.
#feedback Why are there no examples for the must be true and negation tests? I would think that's handy information to have as part of a lesson before moving onto the questions.
The not-stated-fact here that makes this type of question more scary is that Necessary Assumption questions, according to the cheat sheet given to us, are 53% more numerous than the Sufficient Assumption questions :(
When applying the negation test, does it mean that negating the correct answer choice would render the conclusion impossible, or just that the premises would no longer support the conclusion? It makes more sense to me that it would mean that the negation of the answer choice would mean that the conclusion can absolutely no longer be drawn, but there's a few questions in the upcoming lessons where it seems like that isn't the case. Instead, it seems like if the correct answer choice weren't true, that the premises just no longer directly support the conclusion. However, negating the answer choice doesn't seem to preclude the possibility of other assumptions being made that could allow the conclusion to be drawn.
This is a great question and the answer is definitely what you're suspecting. The negation does not need to show that the conclusion cannot be true. It just needs to show that the given premises, without more, are not enough to guarantee that the conclusion is true.
This makes a lot of sense and saves me a lot of confusion. I much better understand these types of questions now. Thanks so much for your response, I appreciate it!
@Kevin_Lin I think it's fair to say that the negation of a NA does not have to make the conclusion impossible. Rather, the negation of the NA makes the premise no longer support the conclusion.
Here, for example, consider the assumption "The amount of aesthetic pleasure a diamond provides is relevant to the value it commands." The negation is The amount of aesthetic pleasure a diamond provides is not relevant to the value it commands. Does that negation mean that the conclusion ("both should be deemed of equal value") is false? No. Maybe the two should still be deemed of equal value for some other, undiscussed reason (e.g. this counterfeit is really rare, counterfeits are actually worth 1000 more than diamonds these days for some strange reason, etc.).
But what does this negation actually do? The negation makes the premise no longer support the conclusion. If it's possible for aesthetic pleasure to be irrelevant to the value (our negation), then the fact that the counterfeit and real diamond provide equal aesthetic pleasure (our premise) does not support the conclusion that the two should be deemed of equal value. Now, faced with this negation, we'd ask ourselves, "So what that the two provide equal aesthetic pleasure?"
Kevin said above that "The negation does not need to show that the conclusion cannot be true. It just needs to show that the given premises, without more, are not enough to guarantee that the conclusion is true." I'm a little concerned with that wording. For NA questions (and S/W, SA, PSA, pretty much all "subjective" questions), we already have an argument where "the given premises, without more, are not enough to guarantee the conclusion." The argument here -- "Counterfeit and real diamonds give the same amount of aesthetic pleasure, hence both should be deemed of equal value" -- already has a conclusion that isn't guaranteed by the premise alone, before we even touch the negation test. All NA questions involve "flawed" arguments in the sense that the argument is not, on its own, fully valid (we have latent assumptions).
All that to say, the negation of a necessary assumption makes the premise(s) no longer support the conclusion.
This was really an exercise to make sure I understood this well -- anyone feel free to push back here!
Does anyone have any tips for coming up with an answer in your head before looking at the answer choices? For example, should we hold the conclusion and think "what if conclusion is true, but..." or is this the wrong way to go about finding a loophole?
Haven't done the module for NA questions yet but I read about it in the LSAT Trainer, if I had to guess I wouldn't try to predict the right answer for this type of question as sometimes arguments can have multiple things be necessary. I would lean towards POE
can someone give an example of using the negation test? i feel like i'm almost there with understanding it... if you contradict the answer choice and it makes the argument invalid, then that's the correct answer?
Hey - let me know if the below example helps w/ regard to the negation test. But for your question, yeah. If the correct answer choice is contradicted (i.e not true) then it will destroy the argument in the stimulus. If an answer choice can be contradicted without necessarily ruining the argument in the stimulus, then it's not necessary / needed.
Ex using the fat cat, salmon trash can situation. Sorry for the low effort answer choices. Detective suspects it's the cat based on the evidence he gives. Which of the following is a necessary assumption?
a) cats can be fat and cute
b) cats are capable of knocking down a trash can
c) cats are always adorable
d) if a cat is adorable, then it is also fat
e) "other irrelevant answer choice"
Correct answer choice is B. Using the negate test, if B is not true (i.e if cats really aren't capable of knocking down a trash can), then the entire argument falls apart. It couldn't have been the obese cat knocking down the trash can to get the salmon if cats are incapable of doing so. This is also an example of the correct answer being necessary but not sufficient because the very fact that cats are capable of knocking down a trash can doesn't mean the obese feline in question did it. It not only is not sufficient to bring about the detective's conclusion, but it also barely moves the needle / barely strengthens the argument. There are lots of things still that could've knocked the trash can over.
The lesson says "That assumption is said to be both sufficient and necessary. But often such distinctions do exist. An assumption can be just sufficient and not necessary. Or an assumption can strengthen an argument without being necessary."
Should it have said, "Or an assumption can strengthen an argument without being sufficient or necessary."
Or maybe it should have said "Or an assumption can be just necessary and not sufficient."
Perhaps I'm missing something here but the way it's written doesn't seem to highlight the distinctions very distinctly.
Where are the example questions on this intro page? This has been big for me in previous lessons. I noticed there weren't any in the last section either.
Another note I tell myself that's very helpful is that:
Necessary assumption answers are airtight. That, without the airtight answer choice, the argument will fail. I also view NA assumptions in a separate category where it's just a fact regardless of whether it strengthens the argument, or not.
Whereas, I view sufficient assumption answers as one of many supporting statements to validate an argument.
When I was going through SA questions, I would find the right answer, but challenge it by thinking of another answer that could replace it. This helped me to discern what makes an answer "airtight" vs. what is just one of many other options.
From my understanding, NA are types of questions that require the answer choice to be strongly true to reach the argument's conclusion. Through doing the Negation test if it destroys the argument then the answer choice is necessary for the argument to reach its conclusion. My concern on the other hand is when I am practicing the questions I get confused about if looking for the NA I am looking for new information OR it is finding gaps such as if something is said in the premise but the conclusion introduces something else. That is why I am getting the answers incorrect.
#feedback this takes way longer than 3 minutes to read and digest. I know it's not a huge deal, but I think it's important to provide accurate time predictions for sections. I've noticed this is a common theme for most reading lessons, that the time it takes to complete is underestimated.
The Pizza Rat is correct. I was zoning out trying to break down every rich detail in this page. It is filled with amazing knowledge but it took me a fat minute to finish it all.
In NA questions, we are being asked to identify how the author got to this point, with the argument as is. Ask yourself, "What is absolutely necessary to have gotten to this point?"
In SA questions, we are being asked to take the argument to the next level by adding to it something that would make it logically valid. Ask yourself, "What can we add to this to make it better?" so to speak
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61 comments
I'm gonna need to think of the phrasing as "strictly necessary"
Wait, can someone explain why the phrase "the amount of aesthetic pleasure a diamond provides is relevant to the value it commands" doesn't justify the conclusion?
I feel like it goes hand-in-hand with the premise and conclusion? The conclusion was that they should be deemed of equal value, and if they both give the same amount of aesthetic pleasure, why would the necessary assumption not justify the conclusion?
@nycxchi aesthetic value may be "relevant to the value it commands"
but it does not tell you enough to say "both should be deemed of equal value"
aesthetic value could, for example be relevant to a very small degree, but there could be some much more important factor to the value a diamond command commands.
it leaves the door open for a possibility such as "the diamond looks good, sure, and that matters a little bit, but the value of knowing a diamond is real matters much more"
in that world, "both should be deemed of equal value" would be false
u can't assume someone knows how to dribble a basketball if they've won 5 MVPs?
@ZachistheLawyerinCharge You misunderstand. He is saying winning 5 MVPS isn't necessary for being one the best players of all time. You could have 4, 3, 2, 10 MVP awards. Who cares if its 5. Who cares if its any. It's not necessary.
@SimonArmendariz I didnt say anything about being one of the best of all time. You misunderstand what I wrote. I said it's safe to assume someone knows how to dribble a basketball if they've won 5 mvps.
@ZachistheLawyerinCharge Ah. I mean that's true that that is a reasonable assumption, but those conditions were never put together like that in the previous lesson's example.
Just to confirm.... is this rule sufficient and necessary? "Rule: the value of a diamond should derive solely from the aesthetic pleasure it provides."
Or, in the example, is it only the rule "the amount of aesthetic pleasure that a diamond provides is relevant to the value that it commands" that is necessary (but not sufficient)?
@e.wimoine To be sufficient it has to strengthen the conclusion to a degree that it is believable and possibly valid. To be necessary it just has to be grounds for which something can be true.
YAYYY, it's a video!!!!!
@MnM its been so long
I’m in a fantasy football league with friends. Quick refresher: you draft real players, set a lineup, and your team scores based on how those players do in real games.
This week Friend 1 was playing Friend 2. The score was 120 to 135. Friend 1 was down 15, and here is the kicker: he left his quarterback slot empty. Friend 2’s whole roster had already played, so 135 was his final score.
I told Friend 1, “If you want any chance to win, you need to start a QB.” Friend 2 jumped in and said, “Even if he adds a QB, that does not mean he will get 16 or more points.” I said, “Right, it is not a guaranteed win. But without a QB, there is zero chance.” That is the point. It is a necessary condition. A QB does not ensure victory, but no QB ensures defeat.
Shoutout to 7Sage. LSAT necessary assumptions can even help you talk trash with logic.
I don't understand how the jewels sentence is not necessary but it is sufficient. I get that it is not as narrowly tailored, but diamonds still fit into the category of jewels so that sentence still applies to them. I feel like the way this concept was explained went completely over my head. I understood everything until that point where it was sufficient but not necessary yet still applicable to diamonds because diamonds are jewels. Unless my problem is that I made the assumption that all diamonds are jewels.
@LSATWarrior My take is that - being able to swap out the word proves it is unnecessary. Necessary means that without that rule, the argument breaks. So you can actually say that about the sufficient answer. You can essentially negate that argument and still get a logical argument. "The value of a jewel should NOT derive solely from the aesthetic pleasure it provides". The argument can still hold true in this case still.
Klay Thompson scored 60 pts on 11 dibbles
Does the LSAT have a question type that requires sufficient and necessary?
no
Sometimes this guy has a weird way of explaining things
So, even though necessary conditions generally cast a wider 'net' (as the large circle with several sufficient conditions inside it) it actually needs to be more specific -- tailored -- to the argument than a sufficient assumption?
thats what im assuming
Yeah because if you falsify a sufficient assumption it does not completely destroy an argument. This is because the argument does not need the sufficient assumption in order to stand.
On the diamond question: another necessary assumption is that diamonds have any value at all. It is necessary for a diamond to have any kind of value in order for its value to be derived from aesthetic pleasure, yet it having any value at all is not sufficient for that argument we're referencing to be true. I think if we were to deny this necessary assumption, it would hurt the diamond-value argument even more than the example given here.
#feedback Why are there no examples for the must be true and negation tests? I would think that's handy information to have as part of a lesson before moving onto the questions.
The not-stated-fact here that makes this type of question more scary is that Necessary Assumption questions, according to the cheat sheet given to us, are 53% more numerous than the Sufficient Assumption questions :(
When applying the negation test, does it mean that negating the correct answer choice would render the conclusion impossible, or just that the premises would no longer support the conclusion? It makes more sense to me that it would mean that the negation of the answer choice would mean that the conclusion can absolutely no longer be drawn, but there's a few questions in the upcoming lessons where it seems like that isn't the case. Instead, it seems like if the correct answer choice weren't true, that the premises just no longer directly support the conclusion. However, negating the answer choice doesn't seem to preclude the possibility of other assumptions being made that could allow the conclusion to be drawn.
This is a great question and the answer is definitely what you're suspecting. The negation does not need to show that the conclusion cannot be true. It just needs to show that the given premises, without more, are not enough to guarantee that the conclusion is true.
This makes a lot of sense and saves me a lot of confusion. I much better understand these types of questions now. Thanks so much for your response, I appreciate it!
@Kevin_Lin I think it's fair to say that the negation of a NA does not have to make the conclusion impossible. Rather, the negation of the NA makes the premise no longer support the conclusion.
Here, for example, consider the assumption "The amount of aesthetic pleasure a diamond provides is relevant to the value it commands." The negation is The amount of aesthetic pleasure a diamond provides is not relevant to the value it commands. Does that negation mean that the conclusion ("both should be deemed of equal value") is false? No. Maybe the two should still be deemed of equal value for some other, undiscussed reason (e.g. this counterfeit is really rare, counterfeits are actually worth 1000 more than diamonds these days for some strange reason, etc.).
But what does this negation actually do? The negation makes the premise no longer support the conclusion. If it's possible for aesthetic pleasure to be irrelevant to the value (our negation), then the fact that the counterfeit and real diamond provide equal aesthetic pleasure (our premise) does not support the conclusion that the two should be deemed of equal value. Now, faced with this negation, we'd ask ourselves, "So what that the two provide equal aesthetic pleasure?"
Kevin said above that "The negation does not need to show that the conclusion cannot be true. It just needs to show that the given premises, without more, are not enough to guarantee that the conclusion is true." I'm a little concerned with that wording. For NA questions (and S/W, SA, PSA, pretty much all "subjective" questions), we already have an argument where "the given premises, without more, are not enough to guarantee the conclusion." The argument here -- "Counterfeit and real diamonds give the same amount of aesthetic pleasure, hence both should be deemed of equal value" -- already has a conclusion that isn't guaranteed by the premise alone, before we even touch the negation test. All NA questions involve "flawed" arguments in the sense that the argument is not, on its own, fully valid (we have latent assumptions).
All that to say, the negation of a necessary assumption makes the premise(s) no longer support the conclusion.
This was really an exercise to make sure I understood this well -- anyone feel free to push back here!
Does anyone have any tips for coming up with an answer in your head before looking at the answer choices? For example, should we hold the conclusion and think "what if conclusion is true, but..." or is this the wrong way to go about finding a loophole?
Thanks :)
Haven't done the module for NA questions yet but I read about it in the LSAT Trainer, if I had to guess I wouldn't try to predict the right answer for this type of question as sometimes arguments can have multiple things be necessary. I would lean towards POE
sweet! thanks for the reply :) will def keep that in mind
can someone give an example of using the negation test? i feel like i'm almost there with understanding it... if you contradict the answer choice and it makes the argument invalid, then that's the correct answer?
Hey - let me know if the below example helps w/ regard to the negation test. But for your question, yeah. If the correct answer choice is contradicted (i.e not true) then it will destroy the argument in the stimulus. If an answer choice can be contradicted without necessarily ruining the argument in the stimulus, then it's not necessary / needed.
Ex using the fat cat, salmon trash can situation. Sorry for the low effort answer choices. Detective suspects it's the cat based on the evidence he gives. Which of the following is a necessary assumption?
a) cats can be fat and cute
b) cats are capable of knocking down a trash can
c) cats are always adorable
d) if a cat is adorable, then it is also fat
e) "other irrelevant answer choice"
Correct answer choice is B. Using the negate test, if B is not true (i.e if cats really aren't capable of knocking down a trash can), then the entire argument falls apart. It couldn't have been the obese cat knocking down the trash can to get the salmon if cats are incapable of doing so. This is also an example of the correct answer being necessary but not sufficient because the very fact that cats are capable of knocking down a trash can doesn't mean the obese feline in question did it. It not only is not sufficient to bring about the detective's conclusion, but it also barely moves the needle / barely strengthens the argument. There are lots of things still that could've knocked the trash can over.
Hope this is somewhat helpful.
thank you so much!
#feedback I miss the videos!
The lesson says "That assumption is said to be both sufficient and necessary. But often such distinctions do exist. An assumption can be just sufficient and not necessary. Or an assumption can strengthen an argument without being necessary."
Should it have said, "Or an assumption can strengthen an argument without being sufficient or necessary."
Or maybe it should have said "Or an assumption can be just necessary and not sufficient."
Perhaps I'm missing something here but the way it's written doesn't seem to highlight the distinctions very distinctly.
Where are the example questions on this intro page? This has been big for me in previous lessons. I noticed there weren't any in the last section either.
Can someone explain the difference between necessary assumptions and sufficient assumptions?
Ok, thank you!! I'm starting to get it
All cats are mammals.
That animal is a mammal, therefore it must be a cat.
Cat→Mammal is correct. (If it is a cat, then it is a mammal)
Mammal→Cat is incorrect. (If it is a mammal, then it is a cat.)
Do you see what is wrong with the reasoning when you mix up the sufficient and necessary conclusions?
Being a cat is sufficient for being a mammal, but it is not necessary.
There are plenty of other types of animals that can be classified as a mammal. Bears, giraffes, and whales are all mammals.
Another note I tell myself that's very helpful is that:
Necessary assumption answers are airtight. That, without the airtight answer choice, the argument will fail. I also view NA assumptions in a separate category where it's just a fact regardless of whether it strengthens the argument, or not.
Whereas, I view sufficient assumption answers as one of many supporting statements to validate an argument.
When I was going through SA questions, I would find the right answer, but challenge it by thinking of another answer that could replace it. This helped me to discern what makes an answer "airtight" vs. what is just one of many other options.
Hope this helps!
can someone summarize what na questions are as simple as possible please thanks
It would be super helpful to include example question in many areas of this lesson so we can get it fully when reading.
From my understanding, NA are types of questions that require the answer choice to be strongly true to reach the argument's conclusion. Through doing the Negation test if it destroys the argument then the answer choice is necessary for the argument to reach its conclusion. My concern on the other hand is when I am practicing the questions I get confused about if looking for the NA I am looking for new information OR it is finding gaps such as if something is said in the premise but the conclusion introduces something else. That is why I am getting the answers incorrect.
#feedback this takes way longer than 3 minutes to read and digest. I know it's not a huge deal, but I think it's important to provide accurate time predictions for sections. I've noticed this is a common theme for most reading lessons, that the time it takes to complete is underestimated.
The Pizza Rat is correct. I was zoning out trying to break down every rich detail in this page. It is filled with amazing knowledge but it took me a fat minute to finish it all.
Took me 20 minutes MR. CHEESE
never thought i'd see such wisdom from Charles Entertainment Cheese
same I thought it was just my ADHD
Come on down the the neighborhood child casino owned by your favorite rat!
FR, I felt like I was reading Heidegger or some philosophical text. Whoever wrote the Mr. Fat Cat example in the comments is the GOAT
me too
I see the difference like this:
In NA questions, we are being asked to identify how the author got to this point, with the argument as is. Ask yourself, "What is absolutely necessary to have gotten to this point?"
In SA questions, we are being asked to take the argument to the next level by adding to it something that would make it logically valid. Ask yourself, "What can we add to this to make it better?" so to speak