Hoping to get a little clarity on when using 'or' vs. 'either/or' affects the overall meaning? In the first example, "You must sit at either one end of the table or the other", it was said that the removal of 'either' did not affect the meaning, given that you must sit at one end and its not possible to sit at both. But in which instances does the use of 'either/or' vs. just 'or' impact the meaning? Could it ever just be 'either' with no 'or'? Thanks!
If the exclusive example given "You must eat either steak or cod, but not both" were written as "You must eat either steak or cod" could it be considered inclusive? Is the "but not both" the indicator of this being an exclusive use of either/or?
Looking some the comments below I see the tutor states the table/sit is exclusive because you can't sit at both places at once. BUT the Eco101/PoliSci101 is inclusive since you could do both. IF that is true then why would the steak/cod statement not be inclusive? can I not eat both? seem we are expected to make assumptions to determine pathways.
@Anthony.pardella@gmail.com The steak/cod example explicitly tells you that it's exclusive. "You must eat either the steak or the cod, but not both." The point they're trying to make is that you should assume the LSAT writers are intending the inclusive meaning of "or", unless there is some part of the stimulus that confirms otherwise. Or, in the case of sitting at the table, it's literally impossible by the laws of time and space for it to be both.
For the option 3 where "or" actually means "and", does that mean "Jane is a faster eater than either Mary or Jon" = "Jane is a faster eater than Mary and John"?
But "Jane is a faster eater than either Mary or Jon" /= "Jane is a faster eater than Mary or Jon"? ... where this now becomes option 2 usage of "or"?
@ahuang for ur second question, i think even the sentence "jane is a faster eater than mary or jon" is still the first usage (inclusive or) bc nowhere does it explicitly say that jane cannot be faster than both (or that the two are mutually exclusive); it simply says she is faster than mary or jon. and if i understood this correctly, then we always should assume that "or" refers to the inclusive or, unless stated otherwise! a tad bit confusing but i hope this helps!
With regard to the chair description does the same trick from the antecedent lesson not work. E.G. Not sitting on the left end of the table is necessary for sitting on the right end of the table, but sitting on the right end of the table is merely sufficient for not sitting on the left end of the table. Is the reason this is Flagged as different the function of the these two options presented within the frame of a logical argument?
#help so inclusive or , jon can take both classes because the sentence is not indicating that he isnt able to not take both like for example "Jon must enroll in Economics 101 or Political Science 101 this semester, but not both" ? someone tell me if i am understanding this pls
I'd like to know how the inclusive example couldn't also be exclusive. What if he can only do poli 101 or econ 101 and not both, just like the chair example? How do they differentiate?
It has to do with the situation. Though, in my limited experience, you must sometimes just take what you read as truth on the LSAT, common sense exist.
In the chair example, you cannot be in both places at once. As likely everyone here has been to college, you know that you are not limited to taking only 1 class during the semester (unless they conflict in time, which would likely be explicitly stated).
You could think of going to a restaurant for another common exclusive.
Soup or Salad.
This may not be a perfect way to describe it, but is how I see the differences. A matter of internal sense in what is possible given the presented situation when inclusivity or exclusivity is not explicitly stated.
If Jon must enroll in Economics 101 or Political Science 101 this semester, how could I make a reasonable assumption that he can also register for both? There's no context in the sentence that indicates that. Especially with the topic of registering for courses, the given sentence really indicates that both are sufficient to fulfill some requirement because he can take either course. So again, why would I assume this is and/or. It just doesn't seem like a logical assumption to make grammatically.
@FaresDaraghmeh This is exactly how I feel, especially since exclusive or does not necessarily need the indicator "either" to be exclusive. It seems like an exclusive or only.
@FaresDaraghmeh There's nothing conceptually that makes registering for Econ 101 and Political Science 101 mutually exclusive. So why would you interpret the statement as exclusive? I think we just need to change our default interpretation. If you don't have language that creates exclusivity, and the concepts themselves don't compel exclusivity, then you should interpret "or" as inclusive.
@Kevin_Lin Is it the word "either" that makes it exclusionary? Because it's stated that the meaning of the first sentence would remain the same with or without the word "either".
eg. You must sit at (either) one end of the table or the other.
I'm not understanding the difference between that sentence and this one:
eg. Jon must enroll in Economics 101 or Political Science 101 this semester.
@180-Energy The difference comes from the underlying concepts. It’s impossible to sit at both ends at the table. So “sit at one end of the table or the other” is exclusive, no matter whether you use “either.” But taking multiple classes isn’t exclusive. It’s not conceptually impossible to take both. So “or” should be read inclusively.
What contextual information about "Jon must enroll in Economics 101 or Political Science 101 this semester" gives it away that it's the "inclusive" or? Since we need to use context to figure out which "or" it is, I'm confused how it's clear just from reading the sentence that Jon could technically pick both classes. Thx in advance!
@AkshayaAnnampedu For me, what give away that it is an "inclusive or" is the fact that there's no language in the sentence making it exclusive. That sounds confusing, but let me explain in comparison to the exclusive example "You must eat either the steak or the cod, but not both"
In Jon's example, he HAS to enroll in either Econ or Polisci, but there's nothing excluding him from taking both. What initially tripped me up was using Lawgic. With Lawgic, we get:
/Econ --> Polisci
/Polisci --> Econ
This mapping of the sentence makes it seem like "oh if he isn't taking econ than he must be taking polisci or vice versa." It seems like it's cut and dry that he's either taking one or the other, but nowhere in the sentence does it say that he's not allowed to take both. Lawgic helps us understand that at the very minimum he HAS to be taking one of those classes, and we can understand that by saying "okay, if Jon isn't taking polisci, then he HAS to be taking econ." However, there's also a world in which he's taking BOTH of those classes, but since we didn't map that out via sufficiency necessity conditions, it was harder (at least for me) to understand that option.
If you compare that to the exclusive example with cod and stake, you can see that really the only difference is the "but not both" at the end of the sentence. You can literally take that at face value - in no world are you allowed to have both the steak and the cod. Because of that, you know that this is an exclusive or because it isn't like the example with Jon where he had the possibility of potentially taking both classes. So, if you can clearly see that there are only two options you can't stray from, then the Group 3 "Negate Sufficient" rule is not applicable anymore.
I'm not sure if this helps with your question about context, but this is how I mapped it out in my head in a way that made sense!
I was thinking about why we might say Jane is a faster eater than either Mary or Jon rather than Jane is a faster eater than Mary and Jon. Is it to rule out any confusion about the sentence being interpreted as saying Jane is a faster eater than Mary and Jon combined?
@HenryLehmann You'd say "Jane is a faster runner than Mary or Jon," and I don't think anyone would reasonably interpret that as them running combined. I think it's just a quirk of the language that you have to know.
This lesson is really confusing me because why do we have to separate them into three meanings and do the negate sufficient indicators apply to all three?
@JenniferQin Both Ors negate the sufficient condition (group 3), but in different ways with different meanings! For the Exclusive Or, where you must sit at either end A of the table or at end B, this translates to: not end A = end B (with only 1 outcome possible). For the Inclusive Or, where Jon must enroll in either Economics 101 or Political Science 101 this semester, this translates to: no Econ 101 = Polysci 101 (though dual enrollment is also possible). However, sometimes either...or can be translated to And, in which case it becomes a conjunction, like where Jane eating her hamburgers and fries faster than Mary and John translates to Jane=faster than Mary and faster than John.
Subscribe to unlock everything that 7Sage has to offer.
Hold on there, stranger! You need a free account for that.
We love that you want to get going. Just create a free account below—it only takes a minute—and then you can continue!
Hold on there, stranger! You need a free account for that.
We love that you came here to read all the amazing posts from our 300,000+ members. They all have accounts too! Just create a free account below—it only takes a minute—and then you’re free to discuss anything!
Hold on there, stranger! You need a free account for that.
We love that you want to give us feedback! Just create a free account below—it only takes a minute—and then you’re free to vote on this!
Hold on there, you need to slow down.
We love that you want post in our discussion forum! Just come back in a bit to post again!
Sorry, you need a subscription for that.
Happens all the time: now that you've had a taste of the lessons, you just can't stop -- and you don't have to! Click the button.
90 comments
Hoping to get a little clarity on when using 'or' vs. 'either/or' affects the overall meaning? In the first example, "You must sit at either one end of the table or the other", it was said that the removal of 'either' did not affect the meaning, given that you must sit at one end and its not possible to sit at both. But in which instances does the use of 'either/or' vs. just 'or' impact the meaning? Could it ever just be 'either' with no 'or'? Thanks!
If the exclusive example given "You must eat either steak or cod, but not both" were written as "You must eat either steak or cod" could it be considered inclusive? Is the "but not both" the indicator of this being an exclusive use of either/or?
even with context, inclusive ors feel like such a stretch to be making assumptions on...
i had to close my eyes and take a moment after this one
who actually came up with this test omg
shoulda kept the tower of babel
I made flash cards to help memorize group 1-4 conditional indicators, thought I’d share in case it would be helpful to anyone else. I’m redoing this course after getting through most of it and taking the lsat and not doing as well as I hoped. Looking back I realize how important it is to know these. https://quizlet.com/1153975729/lsat-7sage-conditional-indicators-to-share-flash-cards/?i=71yhg9&x=1jqY
@Elideebeep thanks so much <3
@carmiilol sure thing :)
seems like we have to make assumptions to differentiate between exclusive or inclusive ?
Looking some the comments below I see the tutor states the table/sit is exclusive because you can't sit at both places at once. BUT the Eco101/PoliSci101 is inclusive since you could do both. IF that is true then why would the steak/cod statement not be inclusive? can I not eat both? seem we are expected to make assumptions to determine pathways.
@Anthony.pardella@gmail.com The steak/cod example explicitly tells you that it's exclusive. "You must eat either the steak or the cod, but not both." The point they're trying to make is that you should assume the LSAT writers are intending the inclusive meaning of "or", unless there is some part of the stimulus that confirms otherwise. Or, in the case of sitting at the table, it's literally impossible by the laws of time and space for it to be both.
For the option 3 where "or" actually means "and", does that mean "Jane is a faster eater than either Mary or Jon" = "Jane is a faster eater than Mary and John"?
But "Jane is a faster eater than either Mary or Jon" /= "Jane is a faster eater than Mary or Jon"? ... where this now becomes option 2 usage of "or"?
@ahuang for ur second question, i think even the sentence "jane is a faster eater than mary or jon" is still the first usage (inclusive or) bc nowhere does it explicitly say that jane cannot be faster than both (or that the two are mutually exclusive); it simply says she is faster than mary or jon. and if i understood this correctly, then we always should assume that "or" refers to the inclusive or, unless stated otherwise! a tad bit confusing but i hope this helps!
"John can eat pumpkin pie or cherry pie"
Applying the concept "and/or", we know that John must eat either eat pumpkin pie, cherry pie, or both!
And/Or is the most common encounter on the LSAT
With regard to the chair description does the same trick from the antecedent lesson not work. E.G. Not sitting on the left end of the table is necessary for sitting on the right end of the table, but sitting on the right end of the table is merely sufficient for not sitting on the left end of the table. Is the reason this is Flagged as different the function of the these two options presented within the frame of a logical argument?
#help so inclusive or , jon can take both classes because the sentence is not indicating that he isnt able to not take both like for example "Jon must enroll in Economics 101 or Political Science 101 this semester, but not both" ? someone tell me if i am understanding this pls
@lemonpie yes I believe the ability distinguish between the "inclusive or" and "exclusive or" use case is based on the context of the sentence.
I'd like to know how the inclusive example couldn't also be exclusive. What if he can only do poli 101 or econ 101 and not both, just like the chair example? How do they differentiate?
@dancingqueen138
It has to do with the situation. Though, in my limited experience, you must sometimes just take what you read as truth on the LSAT, common sense exist.
In the chair example, you cannot be in both places at once. As likely everyone here has been to college, you know that you are not limited to taking only 1 class during the semester (unless they conflict in time, which would likely be explicitly stated).
You could think of going to a restaurant for another common exclusive.
Soup or Salad.
This may not be a perfect way to describe it, but is how I see the differences. A matter of internal sense in what is possible given the presented situation when inclusivity or exclusivity is not explicitly stated.
@DNAlex this is the only way that has made sense to me. Thank you for this lol.
@KaylenRodriguez
Still is fairly confusing. 😭
Good luck on the studies!
If Jon must enroll in Economics 101 or Political Science 101 this semester, how could I make a reasonable assumption that he can also register for both? There's no context in the sentence that indicates that. Especially with the topic of registering for courses, the given sentence really indicates that both are sufficient to fulfill some requirement because he can take either course. So again, why would I assume this is and/or. It just doesn't seem like a logical assumption to make grammatically.
@FaresDaraghmeh This is exactly how I feel, especially since exclusive or does not necessarily need the indicator "either" to be exclusive. It seems like an exclusive or only.
@FaresDaraghmeh There's nothing conceptually that makes registering for Econ 101 and Political Science 101 mutually exclusive. So why would you interpret the statement as exclusive? I think we just need to change our default interpretation. If you don't have language that creates exclusivity, and the concepts themselves don't compel exclusivity, then you should interpret "or" as inclusive.
@Kevin_Lin Is it the word "either" that makes it exclusionary? Because it's stated that the meaning of the first sentence would remain the same with or without the word "either".
eg. You must sit at (either) one end of the table or the other.
I'm not understanding the difference between that sentence and this one:
eg. Jon must enroll in Economics 101 or Political Science 101 this semester.
@180-Energy The difference comes from the underlying concepts. It’s impossible to sit at both ends at the table. So “sit at one end of the table or the other” is exclusive, no matter whether you use “either.” But taking multiple classes isn’t exclusive. It’s not conceptually impossible to take both. So “or” should be read inclusively.
Wait sorry so are all these versions of "or" group 3 indicators or just the inclusive "and/or"
@Moffiemoff all group 3 indicators
@Moffiemoff Just the inclusive one. (By the way, the inclusive reading is by far most common on the LSAT.)
What contextual information about "Jon must enroll in Economics 101 or Political Science 101 this semester" gives it away that it's the "inclusive" or? Since we need to use context to figure out which "or" it is, I'm confused how it's clear just from reading the sentence that Jon could technically pick both classes. Thx in advance!
@AkshayaAnnampedu For me, what give away that it is an "inclusive or" is the fact that there's no language in the sentence making it exclusive. That sounds confusing, but let me explain in comparison to the exclusive example "You must eat either the steak or the cod, but not both"
In Jon's example, he HAS to enroll in either Econ or Polisci, but there's nothing excluding him from taking both. What initially tripped me up was using Lawgic. With Lawgic, we get:
/Econ --> Polisci
/Polisci --> Econ
This mapping of the sentence makes it seem like "oh if he isn't taking econ than he must be taking polisci or vice versa." It seems like it's cut and dry that he's either taking one or the other, but nowhere in the sentence does it say that he's not allowed to take both. Lawgic helps us understand that at the very minimum he HAS to be taking one of those classes, and we can understand that by saying "okay, if Jon isn't taking polisci, then he HAS to be taking econ." However, there's also a world in which he's taking BOTH of those classes, but since we didn't map that out via sufficiency necessity conditions, it was harder (at least for me) to understand that option.
If you compare that to the exclusive example with cod and stake, you can see that really the only difference is the "but not both" at the end of the sentence. You can literally take that at face value - in no world are you allowed to have both the steak and the cod. Because of that, you know that this is an exclusive or because it isn't like the example with Jon where he had the possibility of potentially taking both classes. So, if you can clearly see that there are only two options you can't stray from, then the Group 3 "Negate Sufficient" rule is not applicable anymore.
I'm not sure if this helps with your question about context, but this is how I mapped it out in my head in a way that made sense!
@AnandChoudhary Thank you, this was really helpful!!
I was thinking about why we might say Jane is a faster eater than either Mary or Jon rather than Jane is a faster eater than Mary and Jon. Is it to rule out any confusion about the sentence being interpreted as saying Jane is a faster eater than Mary and Jon combined?
@HenryLehmann You'd say "Jane is a faster runner than Mary or Jon," and I don't think anyone would reasonably interpret that as them running combined. I think it's just a quirk of the language that you have to know.
@brine my point was if you said "Jane is a faster runner than Mary and Jon" that could be confusing
Three different types of or
Inclusive or (and/or)
You can use a pen or marker
Def: You can use just a pan, you can use just a marker, you can use both a pen and a marker
Exclusive or
You must use a pen or marker, but not both
Def: You can use a pen, you can use a market, but you cannot use both. You must choose one or the other, not both
And
The highlighter is better at marking than either the pen or the marker
def: The highlighter is better than the pen and the marker
Inclusive (and/or)
Feel free to grab some snacks or a drink.
Inclusive (and)
The new kitten thinks it is better behaved than either the youngest dog or the eldest dog.
Exclusive
My brother is going to stay up super late or go to bed ridiculously early.
In the inclusive (and/or) it is totally okay for the person to chose both a drink and a snack.
In the and example the new kitten thinks it is better behaved than both to the other options, namely its doggie siblings.
In the exclusive example it is simply not possible to do both.
If the exclusive or are not included in group 3 and shouldn't apply the same rule. Then how do we translate the "exclusive or" into Lawgic?
@LSAT175 You must eat either the steak or the cod, but not both.
[Eat steak-->/Eat cod]
[Eat Cod-->/Eat steak]
i hate this sentence:
because a valid - albeit awkward - interpretation is that she's more devoted to work than either her friends or her family are devoted to work.
as a chronic over-thinker, this kind of sentence is wasted energy for me.
So you're saying "or/either or" can be "and," "or, but not both," as well as...
Where do the "exclusive or" and "simply and" fit into the groups if they do at all?
Isnt inclusive or the same as exclusive or?
If take one or the other.
Is it that in inclusive it can be A and not B or A and B. In exclusive is just A or B, cant have both.
This lesson is really confusing me because why do we have to separate them into three meanings and do the negate sufficient indicators apply to all three?
@JenniferQin Both Ors negate the sufficient condition (group 3), but in different ways with different meanings! For the Exclusive Or, where you must sit at either end A of the table or at end B, this translates to: not end A = end B (with only 1 outcome possible). For the Inclusive Or, where Jon must enroll in either Economics 101 or Political Science 101 this semester, this translates to: no Econ 101 = Polysci 101 (though dual enrollment is also possible). However, sometimes either...or can be translated to And, in which case it becomes a conjunction, like where Jane eating her hamburgers and fries faster than Mary and John translates to Jane=faster than Mary and faster than John.
@LauraByrne Thank you Laura for the explanation!