This was a great lesson on assumptions. I can tell you from studying the LSAT for 2 years now, the absolute most important thing in LR, and honestly, the other 2 sections as well, is to find the assumptions.
But, how do we find the assumptions? First, identify the conclusion, identify the premise(s), and then identify the gap in the argument. If you have this skill at a high level, among a couple other things, then you are taking a huge step to completely conquering LR.
The times I perform the best on LR is when I have the mindset of "I am going to spot some critical assumptions before even looking at the answer choices."
You know what? Sometimes the assumption that you spot before looking at the answer won't help you directly get to the right answer; however, you become aware of "okay, this argument is vulnerable to attack." Once you see that vulnerabilities exist, then it becomes much easier to spot the exact vulnerabilities when they are presented to you in the answer choices.
Where you will run into problems is when you read an argument and you think there is no problem with it at all.
Wait I think I get it now. The mistake we might all be making, is still thinking in the terms of the real world. Now the argument before stated this "Not every mammal is suitable to keep as a pet. After all, tigers are very aggressive and can cause serious injuries to people", since the entire concept of the LSAT is being a persuasive argument and not explicitly relying on reality, I can still ask what if the tiger is not a mammal? Just right there, I weakened the argument in terms of the LSAT and not reality, now let's go further. After they include the assumptions that Tigers are mammals, that aggressiveness causes injuries, therefore not all mammals can be pets, it strengthens the argument yes, however, still makes it weak at the same time. I can even include another assumption, but dogs are kind so why is every mammal not suitable? contrary to the Disney argument which explicitly gave us 2 choices either he proportionated the goats or had to prostate through the alter, we had no links to assume anything else, making is a stronger argument. This is making me feel like I am going crazy
Wow that's so interesting. I completely overlooked the mammals assumption. I understood the assumption about animals being dangerous being a reason for them to not be good pets. However, I didn't really see it as an assumption. In fact, I didn't even question it! Super smart stuff.
This makes sense, but also a tiny bit confused because I thought we weren't supposed to use any outside knowledge, even if it is "common sense". Yes, it is common sense that aggressiveness can cause injuries to people, but I thought we weren't supposed to know that.
@peyt0n I believe this is why the argument is made stronger when you add on "tigers are mammals" or the additional support about aggressiveness. The fact that these are common sense, outside knowledge claims otherwise is what makes them assumptions
I noted the mammal assumption and then told myself I was silly for noting it. That's a nice signpost for how thorough I should be in noting these things.
My issue lies in thinking about the assumptions. They are pretty obvious but for some reason its difficult to think what the assumptions are for an argument. It's only after they acknowledge an assumption that it becomes super clear for me. Whats a method to formulating these assumptions on your own?
@HilarySackor For me, they usually stick out like crazy when I get questions that ask "Which of the following is an assumption that needs to be made for the argument to logically follow?". The thing you have to look for is that these questions will make some kind of claim, and then the conclusion seems to connect to this claim indirectly. So for example:
People that have clean houses do not own messy animals. Peter's house is clean, thus he must not own a pig.
For this argument to logically follow, we must assume that pigs are messy animals. Keep in mind pigs aren't messy because of our common knowledge of how pigs enjoy rolling around in mud, but just because of what the first claim states, and what the conclusion is stating based on the claim. You could say the above example with ANY animal (dog, beaver, cat, etc.) and the assumption would still be the same, but for that animal instead of a pig.
@JamesHague yes, and I almost look at the argument with a critical lens. "How can I attack this argument"? So when I read the initial argument, I immediately asked myself, "Okay, but what if someone wants a pet BECAUSE they are dangerous? Wouldn't that make it suitable?"
@KeziaH19 I don't know how much this helps, but this is different from "making an assumption". This lesson is telling us that assumptions that are not confirmed in an argument will weaken the argument's support. What you mean by making an assumption is assuming something is true without it being stated as such. That advice is still valid, just related to a different context!
So are we trying to always make assumptions for arguments, or only when we need to fill in the gaps? And in that case, how do you know to make it a strong or weak assumption?
@SofiaHaddon assumptions are the missing premise (link) that either the conclusion follows organically or if false, completely wrecks or weakens it. After identifying the premises and conclusion, we have to ask ourselves, is their something missing that would tie this whole thing up more neatly?
Assumptions can be hidden as premise which make them hard to find sometimes. Questioning a statement that contains an opinion or a premise without support makes it an assumption.
I am starting to believe that assumptions can only really weaken an argument. So when we are thinking about assumptions, the next question to ask is "how reasonable is this assumption?" and if that assumption is unreasonable, it really weakens the argument.
So "tigers are mammals" hurts the argument by not being stated. But it doesn't ruin the argument because it's a relatively straight forward fact. However, the second assumption about aggressiveness and injuries is much more unreasonable to make, therefor significantly weakens the argument by leaving it out.
Assumptions are baked in to the argument; that means that making them true goes in favor of the argument, but making them false weakens it. The argument is build up brick by brick and making it false removes one of the bricks of the wall
Im confused with the "If made true, they make the support stronger. If made false, they make the support weaker." How do you decide to make the assumption true or false? I see that making them true in the tiger scenario strengthens the support but how are you supposed to know which way to assume...if its an assumption...?
@molebag In the LSAT, assumption questions are generally framed as "What is the assumption required to make this work?" Not, "is the assumption you're making true or false?" So, for the purposes of this exercise, we can assume the assumption is always true, in the same way the premise is always true. That's what makes it an "invisible premise."
Questions that ask "Which of the following would weaken the argument?" might touch on false assumptions.
In either case, for the purposes of the LSAT, you'll know which way you're supposed to assume.
It's really hard for me to tease out the difference between the strength of an argument and the truthfulness of a claim. It's also really hard to think we've found every assumption.
@Metroidude you can keep wringing a towel and more likely than not, some water will come out, but the longer you wring it, the less water will come out. You can spend a ton of time assuming everything but how reasonable and valid to the question are each of them? I understand your frustration b/c I'm also the same way, but the LSAT is all about time and figuring out which assumptions are the most relevant.
It seems that understanding assumptions ONLY in the context of the argument is important. Assumptions are only aspects of the arguments that are not explicitly stated. The reason the tiger being a mammal is an assumption is because it is not explicitly said to be a mammal in the passage.
Defining assumptions as forgotten premises made the lightbulb go off. I see now how the tiger argument could have been stronger. These missing links can most certainly affect the strength of an argument, as well as undermine one.
How to strengthen the argument? State the unstated assumptions as premises.
Aggressiveness and the potential to cause injuries to people are factors that make an animal unsuitable to keep as a pet. Tigers are mammals. Tigers are very aggressive and can cause serious injuries to people. Therefore, not every mammal is suitable to keep as a pet.
Day-to-day, we skip these premises perhaps because we don’t want to be repetitive or detailed and maybe that’s fine. But such level of detail can make an argument 'bullet-proof' and makes it less likely for criticism to arise. In a way, you are also limiting the scope of your argument to prevent straw arguments.
How does stating assumptions limit the “scope” of and argument and herby strengthen it?
When you're making an argument, the "scope" is essentially the boundary or the limits of what your argument is about. By explicitly stating the assumptions in your argument, you're defining this boundary more clearly.
Let’s look at this through the famous Sam Harris-Ben Affleck argument:
Sam: "Islam has bad ideas (the doctrine). Criticizing the doctrine of Islam does not make you bigoted towards Muslim people."
This statement makes some broad assumptions and sets a wide scope, potentially implying that all of Islam's teachings can be deemed as "bad ideas". This wide scope can lead to misunderstandings, as demonstrated by Affleck's response.
Ben: "How dare you say that? There are 1.5 billion Muslims and they are not all bad people."
Affleck interprets Sam's argument as a critique of all Muslims, which isn't Harris' intention. This happens because the original scope of Harris' argument is broad and could be interpreted in multiple ways.
To limit the scope of the argument and clarify his position, Harris could explicitly state his assumptions:
Sam: "Certain interpretations of the doctrine of Islam, like many other religions, can promote harmful behaviors or ideas. However, this criticism of particular interpretations should not be seen as an indictment of all Muslims or the entirety of Islam. Many Muslims may not follow or support these harmful interpretations, and it's important to differentiate between criticism of specific doctrinal interpretations and bigotry towards an entire group of people."
Here, the scope of the argument is narrower, focused specifically on certain interpretations of Islamic doctrine rather than the entire religion or all its followers. Stating these assumptions makes it harder for the argument to be misinterpreted as a blanket statement about all of Islam or all Muslims, as Affleck initially perceived. It also prevents the argument from being twisted into a straw man argument by clearly defining the context and limitations of the criticism.
150 comments
This was a great lesson on assumptions. I can tell you from studying the LSAT for 2 years now, the absolute most important thing in LR, and honestly, the other 2 sections as well, is to find the assumptions.
But, how do we find the assumptions? First, identify the conclusion, identify the premise(s), and then identify the gap in the argument. If you have this skill at a high level, among a couple other things, then you are taking a huge step to completely conquering LR.
The times I perform the best on LR is when I have the mindset of "I am going to spot some critical assumptions before even looking at the answer choices."
You know what? Sometimes the assumption that you spot before looking at the answer won't help you directly get to the right answer; however, you become aware of "okay, this argument is vulnerable to attack." Once you see that vulnerabilities exist, then it becomes much easier to spot the exact vulnerabilities when they are presented to you in the answer choices.
Where you will run into problems is when you read an argument and you think there is no problem with it at all.
Can I ask why you have been studying the lsat for two years? I am interested to know what your goals are.
@hannahpark14930 Bro is a planted agent from 7sage.
have you taken the test yet officially?
i thought that when you assume you make an ass out of u and me
@lilymader01 must be true
Damn, we really did jump into the meat and potatoes already
People that have good skincare do not use fragranced products. Alexis' skincare is great, so she must not use neutrogena.
Assumption: Neutrogena is a fragranced skin care product.
@AmariWilson How do you attack that gap?
#feedback It would be pretty cool if we could highlight/underline the text in these lessons!
Wait I think I get it now. The mistake we might all be making, is still thinking in the terms of the real world. Now the argument before stated this "Not every mammal is suitable to keep as a pet. After all, tigers are very aggressive and can cause serious injuries to people", since the entire concept of the LSAT is being a persuasive argument and not explicitly relying on reality, I can still ask what if the tiger is not a mammal? Just right there, I weakened the argument in terms of the LSAT and not reality, now let's go further. After they include the assumptions that Tigers are mammals, that aggressiveness causes injuries, therefore not all mammals can be pets, it strengthens the argument yes, however, still makes it weak at the same time. I can even include another assumption, but dogs are kind so why is every mammal not suitable? contrary to the Disney argument which explicitly gave us 2 choices either he proportionated the goats or had to prostate through the alter, we had no links to assume anything else, making is a stronger argument. This is making me feel like I am going crazy
@JimmyCrosbyMalanda i get what you're saying. Thanks this helped me.
@JimmyCrosbyMalanda Your going crazy in the best way possible, you got it all right
@JimmyCrosbyMalanda, This helped me a lot, thank you!
Joe Exoctic strongly disagrees with the second assumption
Premise: Calorie Deficits DO NOT matter because you can just lose weight by working out.
Premise: If you are hungry, it is best to eat less calorie-rich foods such as vegetables and fruits that have fewer calories.
Premise: Eating less food means fewer calories overall.
Conclusion: Therefore, if you are in a calorie deficit, you will lose weight.
Another Example:
Premise: People who care about their weight do not eat sweets. Omar's weight is normal, so he must not eat Hershey's.
Assumption: Hershey's is a sweet.
Wow that's so interesting. I completely overlooked the mammals assumption. I understood the assumption about animals being dangerous being a reason for them to not be good pets. However, I didn't really see it as an assumption. In fact, I didn't even question it! Super smart stuff.
This makes sense, but also a tiny bit confused because I thought we weren't supposed to use any outside knowledge, even if it is "common sense". Yes, it is common sense that aggressiveness can cause injuries to people, but I thought we weren't supposed to know that.
@peyt0n I believe this is why the argument is made stronger when you add on "tigers are mammals" or the additional support about aggressiveness. The fact that these are common sense, outside knowledge claims otherwise is what makes them assumptions
I noted the mammal assumption and then told myself I was silly for noting it. That's a nice signpost for how thorough I should be in noting these things.
My issue lies in thinking about the assumptions. They are pretty obvious but for some reason its difficult to think what the assumptions are for an argument. It's only after they acknowledge an assumption that it becomes super clear for me. Whats a method to formulating these assumptions on your own?
@HilarySackor I also have difficulties in be able to find the assumptions in he argument.
@HilarySackor For me, they usually stick out like crazy when I get questions that ask "Which of the following is an assumption that needs to be made for the argument to logically follow?". The thing you have to look for is that these questions will make some kind of claim, and then the conclusion seems to connect to this claim indirectly. So for example:
People that have clean houses do not own messy animals. Peter's house is clean, thus he must not own a pig.
For this argument to logically follow, we must assume that pigs are messy animals. Keep in mind pigs aren't messy because of our common knowledge of how pigs enjoy rolling around in mud, but just because of what the first claim states, and what the conclusion is stating based on the claim. You could say the above example with ANY animal (dog, beaver, cat, etc.) and the assumption would still be the same, but for that animal instead of a pig.
@JamesHague yes, and I almost look at the argument with a critical lens. "How can I attack this argument"? So when I read the initial argument, I immediately asked myself, "Okay, but what if someone wants a pet BECAUSE they are dangerous? Wouldn't that make it suitable?"
So you can test the strength of an assumption within an argument by negating it. Is that correct?
whats a sufficient assumption
Exactly right! A assumption that if negated wrecks the argument is going to be necessary. The same isn't true for sufficient assumptions.
I get confused by this because I thought a rule of thumb is to never make assumptions on the LSAT
@KeziaH19 I don't know how much this helps, but this is different from "making an assumption". This lesson is telling us that assumptions that are not confirmed in an argument will weaken the argument's support. What you mean by making an assumption is assuming something is true without it being stated as such. That advice is still valid, just related to a different context!
assumption missing link between premise and conclusion
if true makes support stronger
if made false they make support weaker
Loved this particular lesson
So are we trying to always make assumptions for arguments, or only when we need to fill in the gaps? And in that case, how do you know to make it a strong or weak assumption?
@SofiaHaddon assumptions are the missing premise (link) that either the conclusion follows organically or if false, completely wrecks or weakens it. After identifying the premises and conclusion, we have to ask ourselves, is their something missing that would tie this whole thing up more neatly?
Assumptions can be hidden as premise which make them hard to find sometimes. Questioning a statement that contains an opinion or a premise without support makes it an assumption.
I am starting to believe that assumptions can only really weaken an argument. So when we are thinking about assumptions, the next question to ask is "how reasonable is this assumption?" and if that assumption is unreasonable, it really weakens the argument.
So "tigers are mammals" hurts the argument by not being stated. But it doesn't ruin the argument because it's a relatively straight forward fact. However, the second assumption about aggressiveness and injuries is much more unreasonable to make, therefor significantly weakens the argument by leaving it out.
Assumptions are baked in to the argument; that means that making them true goes in favor of the argument, but making them false weakens it. The argument is build up brick by brick and making it false removes one of the bricks of the wall
Im confused with the "If made true, they make the support stronger. If made false, they make the support weaker." How do you decide to make the assumption true or false? I see that making them true in the tiger scenario strengthens the support but how are you supposed to know which way to assume...if its an assumption...?
@molebag In the LSAT, assumption questions are generally framed as "What is the assumption required to make this work?" Not, "is the assumption you're making true or false?" So, for the purposes of this exercise, we can assume the assumption is always true, in the same way the premise is always true. That's what makes it an "invisible premise."
Questions that ask "Which of the following would weaken the argument?" might touch on false assumptions.
In either case, for the purposes of the LSAT, you'll know which way you're supposed to assume.
It's really hard for me to tease out the difference between the strength of an argument and the truthfulness of a claim. It's also really hard to think we've found every assumption.
@Metroidude you can keep wringing a towel and more likely than not, some water will come out, but the longer you wring it, the less water will come out. You can spend a ton of time assuming everything but how reasonable and valid to the question are each of them? I understand your frustration b/c I'm also the same way, but the LSAT is all about time and figuring out which assumptions are the most relevant.
It seems that understanding assumptions ONLY in the context of the argument is important. Assumptions are only aspects of the arguments that are not explicitly stated. The reason the tiger being a mammal is an assumption is because it is not explicitly said to be a mammal in the passage.
Defining assumptions as forgotten premises made the lightbulb go off. I see now how the tiger argument could have been stronger. These missing links can most certainly affect the strength of an argument, as well as undermine one.
How to strengthen the argument? State the unstated assumptions as premises.
Aggressiveness and the potential to cause injuries to people are factors that make an animal unsuitable to keep as a pet. Tigers are mammals. Tigers are very aggressive and can cause serious injuries to people. Therefore, not every mammal is suitable to keep as a pet.
Day-to-day, we skip these premises perhaps because we don’t want to be repetitive or detailed and maybe that’s fine. But such level of detail can make an argument 'bullet-proof' and makes it less likely for criticism to arise. In a way, you are also limiting the scope of your argument to prevent straw arguments.
How does stating assumptions limit the “scope” of and argument and herby strengthen it?
When you're making an argument, the "scope" is essentially the boundary or the limits of what your argument is about. By explicitly stating the assumptions in your argument, you're defining this boundary more clearly.
Let’s look at this through the famous Sam Harris-Ben Affleck argument:
Sam: "Islam has bad ideas (the doctrine). Criticizing the doctrine of Islam does not make you bigoted towards Muslim people."
This statement makes some broad assumptions and sets a wide scope, potentially implying that all of Islam's teachings can be deemed as "bad ideas". This wide scope can lead to misunderstandings, as demonstrated by Affleck's response.
Ben: "How dare you say that? There are 1.5 billion Muslims and they are not all bad people."
Affleck interprets Sam's argument as a critique of all Muslims, which isn't Harris' intention. This happens because the original scope of Harris' argument is broad and could be interpreted in multiple ways.
To limit the scope of the argument and clarify his position, Harris could explicitly state his assumptions:
Sam: "Certain interpretations of the doctrine of Islam, like many other religions, can promote harmful behaviors or ideas. However, this criticism of particular interpretations should not be seen as an indictment of all Muslims or the entirety of Islam. Many Muslims may not follow or support these harmful interpretations, and it's important to differentiate between criticism of specific doctrinal interpretations and bigotry towards an entire group of people."
Here, the scope of the argument is narrower, focused specifically on certain interpretations of Islamic doctrine rather than the entire religion or all its followers. Stating these assumptions makes it harder for the argument to be misinterpreted as a blanket statement about all of Islam or all Muslims, as Affleck initially perceived. It also prevents the argument from being twisted into a straw man argument by clearly defining the context and limitations of the criticism.