Is this a flawed method of reasoning? [Edit:found the Q] Forum

[WilliamStrong]

Preptest 41 [October 2003], LR #2 Question 24 has gotten me thinking. I think it is flawed although I am not 100% sure.

Question:
Newscaster:In order for the public to participate in a meaningful way in the current public policy debate, one requirement is that the issues be stated in terms the public can understand. The mayor's speech has just stated these issues in such terms, so now the public at least might be able to participate in a meaningful way in the current public policy debate.

It is a parallel reasoning question. The correct answer choice (E) has a structure very similar to the stimulus above, which makes it correct. But I am not sure if this constitutes a flawed method of reasoning.

E: One must at least have warm clothing if one is to survive in a very cold climate. Jerome has obtained warm clothing; therefore, he might be able to survive in a very cold climate.

The logical structure is: since B is necessary for A, the fact that B is allowed to happen means that, at least, now A might be able to happen.

Note this never says A will happen, but only that B's existence gives the possibility that A might happen, and maybe referencing to the fact that A had zero chance of occurrence before B, and now possibly has a larger than zero chance of occurrence.

Am I thinking too much or is this really logically flawed?

[WilliamStrong]

bump

[redsox]

Yes, this is logically flawed.

[fra]

I don't think that this is logically flawed. It's also not very helpful though.

If A then B.

A is the sufficient condition, B is the necessary condition. If we know that B occurs then we know nothing about A, it could occur, but it also could not occur. So this isn't super helpful.

A more helpful statement is the contrapositive of the conditional statement, which is:
If NOT(B) then NOT(A)

[Louis1127]

The logical structure is: since B is necessary for A, the fact that B is allowed to happen means that, at least, now A might be able to happen.

Note this never says A will happen, but only that B's existence gives the possibility that A might happen

Yea these two statements are annoying ways of saying what Fra said: That knowing that a necessary condition occurs tells us nothing about the sufficient.

[RZ5646]

Was this actually in a question? If you can give me a PT/section/question reference I'll look it up.

I don't think it's logically flawed because the conclusion is so wishy-washy--"A might be able to happen" is equivalent to "it is possible that it is possible that A is true," which is about the weakest thing you can possibly say about A.

The argument goes:
1. I know nothing about A
2. something irrelevant
3. I still know nothing about A

[WilliamStrong]

Was this actually in a question? If you can give me a PT/section/question reference I'll look it up.

I don't think it's logically flawed because the conclusion is so wishy-washy--"A might be able to happen" is equivalent to "it is possible that it is possible that A is true," which is about the weakest thing you can possibly say about A.

The argument goes:
1. I know nothing about A
2. something irrelevant
3. I still know nothing about A

Found the question, see edit, thanks!

[RZ5646]

Was this actually in a question? If you can give me a PT/section/question reference I'll look it up.

I don't think it's logically flawed because the conclusion is so wishy-washy--"A might be able to happen" is equivalent to "it is possible that it is possible that A is true," which is about the weakest thing you can possibly say about A.

The argument goes:
1. I know nothing about A
2. something irrelevant
3. I still know nothing about A

Found the question, see edit, thanks!

I have that PT so I took a look... fortunately it's a fairly easy parallel reasoning where you just have to match the structure (necessary/sufficient, must be true/can be true); you don't need to know if the argument is flawed or not (I was worried about that, since I had to think about your question for a minute). Unfortunately, that means it doesn't give me any more insight into its validity, so my answer above is still all I've got.... hopefully someone else will respond.

[redsox]

A device must have a battery life of at least 5 hours to be marketed as an Ultrabook. My watch has a battery life of two years; therefore, it might be able to be marketed as an Ultrabook.

[RZ5646]

A device must have a battery life of at least 5 hours to be marketed as an Ultrabook. My watch has a battery life of two years; therefore, it might be able to be marketed as an Ultrabook.

The premises have no meaningful relationship with the conclusion, so idk how to interpret it. You'd probably need training in modal logic to say whether this is technically "flawed" or not.

[redsox]

A device must have a battery life of at least 5 hours to be marketed as an Ultrabook. My watch has a battery life of two years; therefore, it might be able to be marketed as an Ultrabook.

The premises have no meaningful relationship with the conclusion, so idk how to interpret it. You'd probably need training in modal logic to say whether this is technically "flawed" or not.

I'm not sure what you mean.

[Pancakes12]

A device must have a battery life of at least 5 hours to be marketed as an Ultrabook. My watch has a battery life of two years; therefore, it might be able to be marketed as an Ultrabook.

You are saying: If 5 hr -----> ultrabook marketing. 2 yr ------> ultrabook marketing maybe.

The questions says: meaningful participation -----> simple terms. simple terms -----> meaningful participation maybe.

Same thing, right? Not really.

Although it seems like you've put forth an absurd example to show that it is flawed reasoning, you really haven't as the examples aren't as comparable as it first seems. In the first case you KNOW that a watch is not an ultrabook. In the second case, we know nothing that disqualifies meaningful participation by the public. For all we know, it is still a POSSIBILITY because a necessary condition is met. It is not flawed reasoning. It is just not very useful reasoning.

Also, the LSAT always claims when flawed reasoning is used. In this question stem (Which one of the following arguments has a pattern of reasoning most
similar to the one in the argument above?) it is not indicated.

Hope that helps OP.

[RZ5646]

A device must have a battery life of at least 5 hours to be marketed as an Ultrabook. My watch has a battery life of two years; therefore, it might be able to be marketed as an Ultrabook.

The premises have no meaningful relationship with the conclusion, so idk how to interpret it. You'd probably need training in modal logic to say whether this is technically "flawed" or not.

I'm not sure what you mean.

As in, you can't determine if the conclusion is true or false from those premises. They don't force it to be one way or the other.

So I agree that if you have just those 3 statements, the argument is invalid. However, part of me feels like there is some implicit premise from which the conclusion may be derived. It depends on how you interpret "might be able to be" and what your initial state is for things that are in that condition.

For example, if you look at this epistemologically and rewrite the conclusion as "(given these premises) I do not know that the watch cannot be marketed as an ultrabook," that's obviously true, and I feel like you should be able to derive that out of thin air. Not knowing anything about the watch's marketability is your default starting point, so could you make an argument like "starting point: I do not know that the watch cannot be marketed as an ultrabook ... irrelevant stuff ... therefore, I do not know that the watch cannot be marketed as an ultra book."

Honestly I'm probably just way overthinking it, since I seriously doubt this will show up on the LSAT.

[RZ5646]

In the first case you KNOW that a watch is not an ultrabook.

Strictly speaking, you don't even know that... he's pulling things in from outside the argument. If you want to use everyday definitions of things like "ultrabook," you need to add a premise like "x in an ultrabook if x has features a, b, c..." Otherwise we're free to treat these "ultrabooks" and "watches" as completely abstract logical entities that we know nothing about except the 2 conditions he gave.

Letting your audience supply their own definitions to gloss over the gaps is sophistry.

[Pancakes12]

In the first case you KNOW that a watch is not an ultrabook.

Strictly speaking, you don't even know that... he's pulling things in from outside the argument, which I'd call deceptive. If you want to use everyday definitions of things like "ultrabook," you need to add a premise like "x in an ultrabook if x has features a, b, c..." Otherwise we're free to treat these "ultrabooks" and "watches" as completely abstract logical entities that we know nothing about except the 2 conditions he gave.

Yeah I get that we don't "know", but what makes redsox's argument convincing is that in real life we truly know that a watch is definitely not an ultrabook. But yes, on the LSAT we couldn't make that assumption.

[foggynotion]

I don't think this argument is flawed. I also don't think modal logic is necessary to deal with this, or decide whether it's flawed or not. I think the author of the argument is just saying that, in order to achieve a goal, there's a requirement that has to be met. Then he tells us the requirement has been met, so they might be able to achieve the goal. If the author had said that the goal could definitely be achieved, that would be flawed, because it's never stated that the requirement is the only requirement that had to be met to achieve the goal. But here, the author, I feel, is really speaking a little informally. It's like he's saying, "It's not guaranteed that the public can participate in a meaningful way, but since the mayor's speech met the only requirement I knew about, as far as I know, the whole thing is still possible." To throw another analogy into the mix, it's like saying: To bake a cake, you at least have to have eggs. You have eggs; so you might be able to bake a cake." There's no guarantee, but because we know the eggs are necessary, and we have them, the cake remains possible.

Also, while the test usually indicates when the reasoning is flaw, it does not always do so. I have seen some questions where it's not stated that the argument is flawed, but it is flawed all the same.

[Pancakes12]

I don't think this argument is flawed. I also don't think modal logic is necessary to deal with this, or decide whether it's flawed or not. I think the author of the argument is just saying that, in order to achieve a goal, there's a requirement that has to be met. Then he tells us the requirement has been met, so they might be able to achieve the goal. If the author had said that the goal could definitely be achieved, that would be flawed, because it's never stated that the requirement is the only requirement that had to be met to achieve the goal. But here, the author, I feel, is really speaking a little informally. It's like he's saying, "It's not guaranteed that the public can participate in a meaningful way, but since the mayor's speech met the only requirement I knew about, as far as I know, the whole thing is still possible." To throw another analogy into the mix, it's like saying: To bake a cake, you at least have to have eggs. You have eggs; so you might be able to bake a cake." There's no guarantee, but because we know the eggs are necessary, and we have them, the cake remains possible.

Also, while the test usually indicates when the reasoning is flaw, it does not always do so. I have seen some questions where it's not stated that the argument is flawed, but it is flawed all the same.

I would be surprised if this were true for parallel reasoning questions, which this is. It may be true for some question types, but the LSAT always indicates flawed reasoning for parallel questions. But yes I agree with your assessment of the question.

[WilliamStrong]

I don't think this argument is flawed. I also don't think modal logic is necessary to deal with this, or decide whether it's flawed or not. I think the author of the argument is just saying that, in order to achieve a goal, there's a requirement that has to be met. Then he tells us the requirement has been met, so they might be able to achieve the goal. If the author had said that the goal could definitely be achieved, that would be flawed, because it's never stated that the requirement is the only requirement that had to be met to achieve the goal. But here, the author, I feel, is really speaking a little informally. It's like he's saying, "It's not guaranteed that the public can participate in a meaningful way, but since the mayor's speech met the only requirement I knew about, as far as I know, the whole thing is still possible." To throw another analogy into the mix, it's like saying: To bake a cake, you at least have to have eggs. You have eggs; so you might be able to bake a cake." There's no guarantee, but because we know the eggs are necessary, and we have them, the cake remains possible.

Also, while the test usually indicates when the reasoning is flaw, it does not always do so. I have seen some questions where it's not stated that the argument is flawed, but it is flawed all the same.

I would be surprised if this were true for parallel reasoning questions, which this is. It may be true for some question types, but the LSAT always indicates flawed reasoning for parallel questions. But yes I agree with your assessment of the question.

I think I remember there are some parallel reasoning questions where the argument is flawed but the stimulus does not tell you that it is flawed, just that you should parallel it.

[Pancakes12]

I don't think this argument is flawed. I also don't think modal logic is necessary to deal with this, or decide whether it's flawed or not. I think the author of the argument is just saying that, in order to achieve a goal, there's a requirement that has to be met. Then he tells us the requirement has been met, so they might be able to achieve the goal. If the author had said that the goal could definitely be achieved, that would be flawed, because it's never stated that the requirement is the only requirement that had to be met to achieve the goal. But here, the author, I feel, is really speaking a little informally. It's like he's saying, "It's not guaranteed that the public can participate in a meaningful way, but since the mayor's speech met the only requirement I knew about, as far as I know, the whole thing is still possible." To throw another analogy into the mix, it's like saying: To bake a cake, you at least have to have eggs. You have eggs; so you might be able to bake a cake." There's no guarantee, but because we know the eggs are necessary, and we have them, the cake remains possible.

Also, while the test usually indicates when the reasoning is flaw, it does not always do so. I have seen some questions where it's not stated that the argument is flawed, but it is flawed all the same.

I would be surprised if this were true for parallel reasoning questions, which this is. It may be true for some question types, but the LSAT always indicates flawed reasoning for parallel questions. But yes I agree with your assessment of the question.

I think I remember there are some parallel reasoning questions where the argument is flawed but the stimulus does not tell you that it is flawed, just that you should parallel it.

Looks like you're right: http://lsatblog.blogspot.com/2011/04/lo ... w.html?m=1