Most/Some implies Some Are Not? Forum

[gnaterlie]

I have never posted on this forum before, though I’ve been lurking for some time, so if this question is posed incorrectly or has already been answered I apologize. I did a search but couldn’t find what I was looking for.

I have a question about formal logic as it applies to the two LR questions below.

I understand from the LRB that the definition of “most” is “a majority, possibly all,” and for that reason when “most” is true, “some” is true. For example, if most doctors charge patients, then assuming doctors exist, some doctors charge patients.

What I don’t understand is if the statement “most doctors charge patients” implies that “some do not.” From my understanding, since “most” could possibly include “all,” it can’t be said definitively “some do not.”

This question relates to PT 11 S2 #12.

I can see why the answer is E, but I don’t really understand. If most sycamores are larger than the maples, how can it be said with certainty that some of them are not larger (i.e. smaller) than the maples? I was trying to reason it through, thinking that the inherent inference in a most statement is a some statement (what LRB describes as "going against" the arrow) but I'm not sure if that works.

If this claim is valid (that most implies some are not), then I don’t understand PT 10 S4 #20.

If “often the pollinating species is so highly adapted it can feed from…only one species of plant” implies some can feed from more than one plant…why is C incorrect? Originally the reason I thought C was incorrect was because the use of the word “any” is too broad – just because it can feed from more than one doesn’t mean it can feed from any.

Clearly I’m missing some fundamental part of the definitions of these words. Any help would be greatly appreciated!

[TheTopBloke]

Yes. You want to determine whether it is absolute. All or none. Some is some, and some may be most, but it's not all.

Most is not all, not absolute. Only None or all, 0% or 100%. Anywhere in between is not absolute. So most is not all, and cannot properly be implied as all. Most and some are vague terms. You cannot determine accurately what it is, however even assuming 'most' is 99%, then 'some', 1% is not.

I too read the LR bible, and while it's not at all horrible, there are far better books out there. I'm assuming you have not taken a logic course, and if you can I highly recommend. If you cannot, then I highly recommend finding a book, not on the LSAT, but on logic and critical thinking.

I wish I had done this prior, because having the foundation is far better than learning a few tricks in the bibles, and this LSAT voodoo will make a whole lot more sense. Plus, you'll get a big boost of confidence which is sure to help your performance on game day.

Good luck!

[Audio Technica Guy]

most and some definitely do NOT imply not all.

Most and some both allow all.

I vaguely remember the question you are talking about, and I don't think that is the issue there. Though it will take me a bit to track the actual question down. If you want to PM me a word for word transcription of the argument and the relevant answer choices, I can help you out that way too.

[Audio Technica Guy]

Yes. You want to determine whether it is absolute. All or none. Some is some, and some may be most, but it's not all.

This is incorrect as far as the LSAT goes. As far as the LSAT goes, if a statement says some or most, then it's possible that it is all.

On the LSAT the two statements "some people got 180's" and "everyone got 180's" could, in LSAT logic, both be true simultaneously.

[gnaterlie]

Yes. You want to determine whether it is absolute. All or none. Some is some, and some may be most, but it's not all.

This is incorrect as far as the LSAT goes. As far as the LSAT goes, if a statement says some or most, then it's possible that it is all.

On the LSAT the two statements "some people got 180's" and "everyone got 180's" could, in LSAT logic, both be true simultaneously.

But in LR, if the stimulus says "some people got 180s" you cannot necessarily say "everyone got 180s" in response to be a MBT question...right? However, from my understanding, if the stimulus says "everyone got 180s" an answer that says "some people got 180s" is correct.

[dominkay]

Yes. You want to determine whether it is absolute. All or none. Some is some, and some may be most, but it's not all.

This is incorrect as far as the LSAT goes. As far as the LSAT goes, if a statement says some or most, then it's possible that it is all.

On the LSAT the two statements "some people got 180's" and "everyone got 180's" could, in LSAT logic, both be true simultaneously.

But in LR, if the stimulus says "some people got 180s" you cannot necessarily say "everyone got 180s" in response to be a MBT question...right? However, from my understanding, if the stimulus says "everyone got 180s" an answer that says "some people got 180s" is correct.

If the stimulus says that "some people got 180s," you cannot necessarily conclude that "everyone got 180s," but neither can you conclude that "some people didn't get 180s."

[dutchstriker]

What I don’t understand is if the statement “most doctors charge patients” implies that “some do not.” From my understanding, since “most” could possibly include “all,” it can’t be said definitively “some do not.”

This question relates to PT 11 S2 #12.

I can see why the answer is E, but I don’t really understand. If most sycamores are larger than the maples, how can it be said with certainty that some of them are not larger (i.e. smaller) than the maples? I was trying to reason it through, thinking that the inherent inference in a most statement is a some statement (what LRB describes as "going against" the arrow) but I'm not sure if that works.

As others have said, most does not imply or rule out the possibility of "all."

The problem you're having with that question is not one of a misunderstanding of a definition. You just didn't read the question closely enough.

First of all, we're talking about age, not size, of the trees. Not hugely important to this question, but close reading is important on the LSAT. More importantly, the question says, "A majority, but not all, of the garden's sycamores are older than any of its maples."

So you don't need to be making any assumptions on this question, as it's worded very clearly.

[romothesavior]

Yes. You want to determine whether it is absolute. All or none. Some is some, and some may be most, but it's not all.

Most is not all, not absolute. Only None or all, 0% or 100%. Anywhere in between is not absolute. So most is not all, and cannot properly be implied as all. Most and some are vague terms. You cannot determine accurately what it is, however even assuming 'most' is 99%, then 'some', 1% is not.

I too read the LR bible, and while it's not at all horrible, there are far better books out there. I'm assuming you have not taken a logic course, and if you can I highly recommend. If you cannot, then I highly recommend finding a book, not on the LSAT, but on logic and critical thinking.

I wish I had done this prior, because having the foundation is far better than learning a few tricks in the bibles, and this LSAT voodoo will make a whole lot more sense. Plus, you'll get a big boost of confidence which is sure to help your performance on game day.

Good luck!

This is flat out wrong. Do not listen to this.

As some have noted, some can be all.

[gnaterlie]

What I don’t understand is if the statement “most doctors charge patients” implies that “some do not.” From my understanding, since “most” could possibly include “all,” it can’t be said definitively “some do not.”

This question relates to PT 11 S2 #12.

I can see why the answer is E, but I don’t really understand. If most sycamores are larger than the maples, how can it be said with certainty that some of them are not larger (i.e. smaller) than the maples? I was trying to reason it through, thinking that the inherent inference in a most statement is a some statement (what LRB describes as "going against" the arrow) but I'm not sure if that works.

As others have said, most does not imply or rule out the possibility of "all."

The problem you're having with that question is not one of a misunderstanding of a definition. You just didn't read the question closely enough.

First of all, we're talking about age, not size, of the trees. Not hugely important to this question, but close reading is important on the LSAT. More importantly, the question says, "A majority, but not all, of the garden's sycamores are older than any of its maples."

So you don't need to be making any assumptions on this question, as it's worded very clearly.

I realized this while rereading the problem ><". It would pay to actually read the problem the first time...

Thanks everyone for the responses! It all makes a lot more sense now.

[dub]

Yes. You want to determine whether it is absolute. All or none. Some is some, and some may be most, but it's not all.

Most is not all, not absolute. Only None or all, 0% or 100%. Anywhere in between is not absolute. So most is not all, and cannot properly be implied as all. Most and some are vague terms. You cannot determine accurately what it is, however even assuming 'most' is 99%, then 'some', 1% is not.

I too read the LR bible, and while it's not at all horrible, there are far better books out there. I'm assuming you have not taken a logic course, and if you can I highly recommend. If you cannot, then I highly recommend finding a book, not on the LSAT, but on logic and critical thinking.

I wish I had done this prior, because having the foundation is far better than learning a few tricks in the bibles, and this LSAT voodoo will make a whole lot more sense. Plus, you'll get a big boost of confidence which is sure to help your performance on game day.

Good luck!

some of your posts are bad.

[TheTopBloke]

Some, or most, may imply all?

I'm not just stating this out of my own belief. This is what I was taught, so please explain, because apparently what I was taught was incorrect. I wouldn't be surprised. I gave my professor an LSAT question which I had gotten incorrect and even he got it incorrect.

[TheTopBloke]

some of your posts are bad.

Nobody's perfect.

[Audio Technica Guy]

Some, or most, may imply all?

I'm not just stating this out of my own belief. This is what I was taught, so please explain, because apparently what I was taught was incorrect. I wouldn't be surprised. I gave my professor an LSAT question which I had gotten incorrect and even he got it incorrect.

Some doesn't ever imply all, it just doesn't rule it out.

[suspicious android]

some of your posts are bad.

Nobody's perfect.

I thought you were gonna get blasted in this thread, but your affable willingness to be proven wrong makes you a good dude in my book.

Consider the following scenario: there are three people in a room, Alvin, Bobby and Charles. They are all boys who were born and raised in California.

Some of the people in the room are male human beings. True or False?

Most of the boys were born in America. True or False?

I think it's uncontroversial that both of those statements are true. For the first one to be false, you'd have to accept the proposition that it is not the case that some of the people in the room are male human beings, ie. none of the people in the room are male human beings. For the second statement to be false you'd have to believe that it's not the case that most of the boys were born in America, ie. half or fewer of them were born in America.

Some of course, does NOT imply all. It only implies some. But just because something is not implied does not mean it must be false. Same with most. Since the example statements could be validly applied to our scenario, we can see that neither "some" nor "most" imply "not all". This is true not just in "LSAT world" but according to normal rules of grammar as well.