There's a typo in this. In the 'lets review' section it says "in this instance, an 'all' relationship, you are trying deny that relationship." There is a 'to' missing- it should read "trying to deny that relationship."
So, in this lesson we're learning how to negate a relationship, but previously we were negating conditions/logic? I'm a bit confused on how to put into words the difference between
A->B
/B->/A
and this new process that goes:
A->B
AB
If the indicator word is "all", how do you know whether to take the negation of the sufficient condition or this new negation process for "some"? Or does it boil down to what the question stem asks? Thanks in advance for any help, I'm a bit too confused to explain what exactly is confusing me...
Couldn't we just say "not all dogs are friendly" in order to negate "all dogs are friendly"? Is there a difference between "not all dogs are friendly" and "some dogs are not friendly"?
#feedback HELP!!!. I don't get this at all. What we learned in previous lessons says that If A---B. How is that not any different then ALL A are B. A---B. its just so counter intuitive I don't get it. IF you say all dogs are friendly how is the negation not all dogs are friendly.All means all there is no room for other dogs..
#feedback It's not clear with how this lesson is written whether or not "It's not the case that all dogs are friendly" can include the possibility that "No dogs are friendly". Translating it into "some dogs are not friendly" would exclude "no dogs are friendly", since we learned earlier that "some" has a lower boundary of 1. However, from a common sense perspective, it seems to me that "it's not the case..." should include the possibility that "no dogs are friendly".
negation: 'none of dogs are friendly' or 'at least one dog is not friendly' or 'some dogs are not friendly'. There is the possibility that 0% to 99% dogs are not friendly.
It seems that 'some dogs are not friendly' implies that 'all dogs are not friendly, because 'some' can imply 'all'.
If it’s a negation, we put a “not” in front of the word
So “all dogs are friendly” turns into “not all dogs are friendly”
But some = doesn’t have to be, but could be true that it means “all”
So how are we allowed to say that some dogs are not friendly, assuming some could mean all. If this is true, we’re literally saying that’s it’s possible that all dogs could not be friendly
If we phrase the negated condition as, “It is not the case that all dogs are friendly,” I’m unclear regarding why our inference from the negation is, “Some dogs are not friendly.” Why are we using the plural expressions of “some” and “dogs”? Isn’t the correct (or at least more accurate/incisive) inference of our negated expression simply, “At least one dog is not friendly”?
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95 comments
Original: All A are B
Negated: Most A are not B ?
I'm confused on why it can't be "Not all A are B" instead of bringing some in it
I am going crazy. Why isn't the negation "if you are not friendly, then you must not be a dog" ?
How can not all mean some if some can mean all?
So looking it from point of view of sets and subsets we notice that
Original: D → F
implies that Dogs is a subset of Friendly.
Whereas negated...
Negated: /(D → F)
The Dogs set is intersecting with the Friendly set? and some dogs are outside the Friendly set intersection.
https://miro.com/app/board/uXjVJL9zNgA=/?share_link_id=597707785172
Would that be correct? If so how can we get more out of thinking in sets?
Is there a drill set or specific questions to practice with quantifiers? This is one area where I struggle a lot.
There's a typo in this. In the 'lets review' section it says "in this instance, an 'all' relationship, you are trying deny that relationship." There is a 'to' missing- it should read "trying to deny that relationship."
For a nessscary assumptipn is this similar?
So, in this lesson we're learning how to negate a relationship, but previously we were negating conditions/logic? I'm a bit confused on how to put into words the difference between
A->B
/B->/A
and this new process that goes:
A->B
AB
If the indicator word is "all", how do you know whether to take the negation of the sufficient condition or this new negation process for "some"? Or does it boil down to what the question stem asks? Thanks in advance for any help, I'm a bit too confused to explain what exactly is confusing me...
To negate:
All --> 99%
Most --> 49%
Some --> 0
None --> 1
#Feedback, can I accurately negate "all" using "some" without having to use the " It is not the case" preface statement.
Couldn't we just say "not all dogs are friendly" in order to negate "all dogs are friendly"? Is there a difference between "not all dogs are friendly" and "some dogs are not friendly"?
#feedback HELP!!!. I don't get this at all. What we learned in previous lessons says that If A---B. How is that not any different then ALL A are B. A---B. its just so counter intuitive I don't get it. IF you say all dogs are friendly how is the negation not all dogs are friendly.All means all there is no room for other dogs..
cats --> friendly
/friendly --> /cat
Is this the same as
it is not the case that all cats are friendly? meaning there is some cats that are not friendly?
I had a whole question typed out here, and then I drew it in the circle graph and it made sense! hahaha
#feedback It's not clear with how this lesson is written whether or not "It's not the case that all dogs are friendly" can include the possibility that "No dogs are friendly". Translating it into "some dogs are not friendly" would exclude "no dogs are friendly", since we learned earlier that "some" has a lower boundary of 1. However, from a common sense perspective, it seems to me that "it's not the case..." should include the possibility that "no dogs are friendly".
Can someone point out an LSAT question where this would appear
For everyone confused, look up Aristotle's square of opposition. It should make this lesson very clear.
In general, I don't like how the word "negated" is used in 7sage to mean contradictory in some cases and contrary in other cases.
so is it still correct to say, "Not all dogs are friendly." ?
can the negation also be that some dogs are friendly?
could you just write, some dogs are friendly, instead of some dogs are not friendly? is it the same thing?
All dogs are friendly.
My understanding of negation:
negation: 'none of dogs are friendly' or 'at least one dog is not friendly' or 'some dogs are not friendly'. There is the possibility that 0% to 99% dogs are not friendly.
It seems that 'some dogs are not friendly' implies that 'all dogs are not friendly, because 'some' can imply 'all'.
Correct me if I am wrong!
#help
If it’s a negation, we put a “not” in front of the word
So “all dogs are friendly” turns into “not all dogs are friendly”
But some = doesn’t have to be, but could be true that it means “all”
So how are we allowed to say that some dogs are not friendly, assuming some could mean all. If this is true, we’re literally saying that’s it’s possible that all dogs could not be friendly
If we phrase the negated condition as, “It is not the case that all dogs are friendly,” I’m unclear regarding why our inference from the negation is, “Some dogs are not friendly.” Why are we using the plural expressions of “some” and “dogs”? Isn’t the correct (or at least more accurate/incisive) inference of our negated expression simply, “At least one dog is not friendly”?
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