Q22 - The druid stones discovered in

[yoohoo081]

So, I'm having difficult time figuring out the wording between B & E.
Could someone explain the differences in plain words?
THANK YOU!

Argument:
druids in ireland=very very old (All -> same quality)
Druid in scotland= more recent (different place-> more recent than other location)

B: takes the fact that MOST members of a group have a certain property to constitute evidence that ALL members of the group have that property

E: takes the fact that ALL members of a group have a certain property to constitute evidence that the members of the group are the ONLY thing with that property

[Shiggins]

I also came down to B and E.

The simulus says that:

Druid stones in Ireland -> very old

Druid stones in Scotland -> recent vintage or in other words not very old

Well from the first claim we know druid stones in Ireland are very old. Being in Irleand is sufficient to say it is very old.

The conlusion is that the Druid Stones in Scotland are not old. Well why not? Being in Ireland is only sufficient to say they are old.

The second sentence on Druid Stones Scotland is saying this as well:
Scotland -> recent vintage (conclusion)
not from Ireland -> not old.

So an improper negation of the first term mixes the sufficient and necessary terms. When that happens the argument here is assuming there is "only" one possible way to have the outcome.

Answer choice B is not trying to spread the very old to all druid stones.

The druid stones in Ireland are old. I believe if it concluded something along the lines of all the stones in Scotland are old as well then this choice would probably be more fitting. But it is not extending that invitation to all stones.

This is how I went over reviewing this question. I hope it helps. If someone wants to add, correct me, or anything else.
Much appreciated.

[ohthatpatrick]

Great explanation.

This argument is really just

Prem:
If druid stone found in Ireland --> old

Prem:
This druid stone NOT found in Ireland

Conc:
hence, NOT old

Classic illegal negation.

Let me give you a couple plain words examples of the flaw (B) is describing vs. the flaw (E) is describing.

(B) says that the premise is "most A are B" and then the conclusion is that "all A are B".

Example:
Most babies are cute. Thus, since Ernie is a baby, we can conclude that Ernie is cute.

For this to have matched the original argument, we would have needed something like:

MOST druid stones in Ireland are very old. Since this druid stone was discovered in Ireland, therefore, it must be very old.

(E) is saying we get a premise that says "All A's are B" and then we conclude that "anything that is ~A must be ~B"

Example:
All babies are cute. Thus, since Ernie is a puppy, we can conclude that Ernie is not cute.

Let me know if you have any lingering questions.

fyi,
(A) describes the Equivocation flaw ... using to different meanings of the same word ... this is frequently offered as an incorrect answer ... it's probably only really the flaw 10% of the time we see it offered as an answer choice.

(C) describes the Circular Logic flaw ... the conclusion is just a restatement of the premise, so there's no way to argue with the logic ... this is ALMOST ALWAYS an incorrect answer ... it's probably only really the flaw 2% of the times we see it
as an answer choice.

(D) is what is known as Inductive reasoning ... drawing a conclusion about future cases based on a what has been true for past cases (in the real world, it's useful to assume the sun will rise tomorrow, since it did yesterday, and the day before that .... but Inductive reasoning is still a Flaw in the deductive world of the LSAT)

[shaynfernandez]

Could use some help on this, I originally chose E when doing this under time eliminating A,B,D very quickly. I went with E because as you said AC C is wrong a large portion of the time. However when I went back through to see if my logic was the same after I finished these problem sets I thought that E was wrong and C was correct.

I went against E because it says "that the members of the group are the ONLY things with that propery."

Well from my understanding of the argument the supporting premise is that all druin stones from Ireland are very very old... Ok so how old is very very old? 1000 years lets say. Ok.
Well our conclusion is that druid stones from Scotland are more recent.

But the premise never establishes that say Spanish druin stones or English druin stones aren't very very old. What if they are older, equal or roughly the same age? Can we really generalize what constitutes very very old?

For those reasons I don't see the core making this assumption... I don't see how the conclusion could land even if he assumed Scottish Druids are not as old... They could still be very very old.

So I chose C because if the author is assuming they are more recent then he can conclude they are more recent (obviously it would be a flaw). Yet I hate the circular reasoning answers because I don't know that I have ever seen a answer that assumes a premise. If it assumes a premise how would it be an assumption...?

Any help would be appreciated.

[ohthatpatrick]

I think you're introducing confusion into the mix by bringing up Spanish/English stones.

You were thinking, "Man, the ramifications of (E) mean that the author has a belief about Spanish druid stones (not very,very old), Turkish druid stones (not very, very, old), etc. ..."

And this concerned you since the author clearly never brought up anything resembling all the other nations of the world (so how could he be assuming something that would affect his judgment of druid stones from all other nations of the world?)

What we need to be more focused on is how the bad logic was put together when it comes to Irish druid stones / Scottish druid stones.

The author's conclusion:
This druid stone is of more recent vintage.
Why?
It was discovered in Scotland.
+
The druid stones discovered in Ireland are very, very old.

Let's put aside the Ireland premise for a second.

If an author said:
This druid stone was discovered in Scotland. Thus, this druid stone is of recent vintage.

This would still NOT be a circular argument.

A circular argument almost never happens on LSAT because it sounds so weirdly dumb and repetitive.

Circular arguments:
LeBron James is the best NBA player. After all, all the other NBA players aren't as good.

We can't go to the circus today. Thus, the probability of us going to the circus today is zero.

====
There's no way to argue with a circular argument because the the conclusion is a restatement of the premise.

Again, if an author said:
This druid stone was discovered in Scotland. Thus, this druid stone is of recent vintage.

(C) could not be our answer. The premise and the conclusion say two different things. The thing the author "takes for granted" (assumes) in this argument is that "any druid stone discovered in Scotland is of recent vintage". Is that the same wording as what the conclusion says? No. The conclusion doesn't even mention Scotland.

Back to the entire argument:
This druid stone is of more recent vintage.
Why?
It was discovered in Scotland.
+
The druid stones discovered in Ireland are very, very old.

LSAT wants us to understand how the author was trying to make his bad argument. The test expects us to see that "more recent vintage" relates to "very, very old". The former is not the same as the latter. The test expects us to see that "discovered in Scotland" relates to "discovered in Ireland". The former is not the same as the latter.

So this author is thinking, "since discovered in Scotland isn't the same as discovered in Ireland, then the age of this Scottish druid stone won't be the same as 'very, very old'."

The way we unpack choice (E) is to ask ourselves whether it matches the premise / conc /reasoning.

An answer choice that says the author "takes the fact that X to constitute evidence that Y", means that X is our premise and Y is our conclusion.

Did we have a premise that "all members of a group have a certain property"? Yes. All druid stones discovered in Ireland have the property of being 'very, very old'.

Does the author's conclusion act like something that WASN'T a druid stone discovered in Ireland DOESN'T have the property of being "very, very old"? Yes.

Conditionally, the statement "all Irish DS are very, very old" looks like:
IrishDS --> very, very old

Conditionally, the statement "Irish DS are the only things that are very, very old" looks like:
~(IrishDS) --> ~(very, very old)

The way the author goes from
ScottishDS --> more recent vintage
matches this second conditional.

Hope this helps.

[shaynfernandez]

Thank you Patrick that helps a lot!

[lsatzen]

Hi All,

I've been drilling Flaw questions and discovered that I do not have a firm grasp on what Circular Reasoning entails. On three separate questions, I was incredibly tempted with answer choices that charged the author with begging the question.

I tried to force answer choice (C) by thinking:
Well one assumption the author is making is that, if a druid stone is discovered in Scotland, then it must be older than a druid stone discovered in Ireland. He is equating the two terms, and thus making them identical. Being "discovered in Scotland" just is "being more recent vintage" than the stones in Ireland. The circularity in his logic can be found in the fact that he is equating being discovered in Scotland with being older, i.e. he is concluding the same thing as what is said in the premises.

Is this thinking incorrect, because the author is only assuming that the two ideas are identical, but without the assumption, they are not actually identical? But, if we plug in the assumption, wouldn't it constitute an error of circular reasoning?

EDIT: An assumption is not directly a part of the argument. So, the hypothetical situation of "plugging it in" should not be used to analyze whether or not an argument is committing a flaw of circular reasoning.

My pre-phrase for this question was, "well who said druid stones from Scotland can't be just as old, if not older than, the druid stones discovered in Ireland?"

Which led me to AC (E).

[ohthatpatrick]

A circular argument is described as:

assumes what it sets out to prove
presupposes what it seeks to establish
the conclusion is merely a restatement of the premise

First and foremost, STOP guessing circular reasoning.

It's wrong over 95% of the time you'll see it.

Here are some circular arguments:

Chocolate is the best flavor of ice cream. After all, consider all the other flavors: none of them are as good as chocolate.

Since all evil traces back to money, money is the root of all evil.

God must exist, because it's impossible for God not to exist.

============

Notice the repetition? These arguments sound stupid because they are just two ways of saying the same thing.

The argument in Q22 can't be circular in part because there are 2 premises. A circular argument really is just premise = conclusion

But this argument is

P1: Irish stones are old.
P2: This stone is Scottish.
Conc: This Scottish stone is younger than Irish ones.

In order for this to be a circular argument, you'd need a premise that sounded like "these Irish stones are older than this Scottish one."

I can see where you tried to make Circular work here, since the author is REALLY forcing a stupid idea on us. But even though he's assuming something stupid, he's not assuming the conclusion.

He's assuming that "only Irish stones are very, very old".

He's taking that for granted, but that's the not "the very claim that he sets out to establish" ... i.e., that's not his conclusion.