Q21 - Terry: Some actions considered

[clarafok]

hello,

can someone please explain why the answer is D and not B? I understand how D explains Terry's flaw, but i don't really see how D explains pat's argument!

thanks in advance!

[giladedelman]

Thanks for posting!

I feel your pain on this one. My first time through, I saw Terry's flaw immediately, but was less sure how to describe Pat's flaw. So I went to the answer choices, figuring it would become clearer to me once I eliminated the incorrect ones.

As it turned out, I found the wrong answers pretty easy to identify.

(A) is out of scope with respect to both arguments. Neither one has anything to do with one property being "one of many."

(B) is incorrect because neither argument goes from "most" to "all." In fact, neither one mentions "most" at all!

(C) is out of scope because both arguments are about "our society."

(E) is no good because the arguments aren't at all interested in distinguishing good and bad actions from "actions of other types."

Okay, now that we've narrowed it down, let's see what's happening in these arguments.

Ted says that an action is good only if it has favorable consequences. That means favorable consequences are a necessary condition of good actions. But then he concludes that, because some actions considered to be bad have favorable consequences, they are really good actions. Well, that would be true if favorable consequences were a sufficient condition of good actions, rather than a necessary one.

So Terry clearly confuses necessary for sufficient. It turns out that Pat does the same thing; it's just a little harder to spot.

Pat rejects Terry's premises and gives us some new ones:

- some good actions don't have favorable consequences
- no actions considered bad have good consequences

How do these lead to the conclusion that some actions considered bad are actually good? Well, if we rephrase that second premise, we can say "All actions considered bad DO NOT have good consequences." So not having good consequences is a necessary condition of actions considered bad.

Now, some good actions share this condition, according to the first premise. So if it were a sufficient condition of actions considered bad, then the fact that some good actions have it would guarantee that those good actions are also actions considered bad, and vice versa. So Pat is also mistaking necessary for sufficient.

Does that make sense? Let me know if you're still confused.

[maryxli]

I am confused. According to LSAT december, 1999-s2.21, when there is 'some', 'many' in a sentence, you cannot apply the conditional rule such as a->b. Therefore, i think none of the answers are correct, the error reasoning is just stated above. Can anyone explain my concern?

[stm_512]

I think the most efficient way of approaching this question is first, by a process of elimination.

A), B), C), and E) aren't as attractive as D) because it's easy to spot Terry's flaw of mistaking a necessary assumption with a sufficient assumption.

I spent a good 15 minutes to half an hour staring at the stimulus trying to figure out how Pat commits the same flaw, and I was still confused even after reading giladedelman's response.

Today I looked at this question and read giladedelman's response again, and I think I finally figured it out.

I think the best way to approach this question, as I already said, is to eliminate all the other answer choices and choose D) because Terry for sure commits the flaw described in this answer choice, if short on time.

If a test-taker finishes the section and has time leftover to check, the best way to attack this question is to assume that Pat is also making the flaw of mistaking a necessary assumption with a sufficient assumption.

Then pick out the conditional, "no actions considered to be bad by our society have favorable consequences".

Mentally diagram this as: Bad Action --> ~ Favorable consequences. We now have what we looked for - unfavorable consequences is the necessary assumption for bad action.

Since we are assuming Pat is also mistaking necessary with sufficient, turn this conditional around to: ~ Favorable consequences --> Bad Action.

Then link Pat's other premise, "Some good actions actually do not have favorable consequences", to the one above.

The chain becomes: Some good actions --> ~ Favorable consequences --> Bad action. Which means that some good actions are bad, which also means that some bad actions are good, arriving at Pat's conclusion (identical to Terry's).

[gaheexlee]

Ted says that an action is good only if it has favorable consequences. That means favorable consequences are a necessary condition of good actions. But then he concludes that, because some actions considered to be bad have favorable consequences, they are really good actions. Well, that would be true if favorable consequences were a sufficient condition of good actions, rather than a necessary one.

I'm a bit confused about this part. I diagrammed this and feel like there isn't a logical error.

Premise 1: "Some actions that are bad have favorable consequences"
Bad ---some---> favorable

Premise 2: "An action is good only if it has fav consequences"
Good ------> favorable

Conclusion: "Some actions are bad are actually good"
Bad ---some---> good

Since Premise 1 is a "some statement" and so can be reversed to say "favorable ---some---> bad," can't you link this with Premise 2 to say:
Good ----> favorable ---some---> bad

Therefore, Good ---some---> bad. And (correctly reversed again since this is another some statement), you can say bad ---some ---> good, which is exactly what Terry says.

Pat does the same thing and reverses a some statement to link the conditionals together.

Can someone please explain where I went wrong?

[nja21]

Pat says:
some good actions have ~(favorable consequences ),
actions considered bad --> ~(favorable consequences)
and concludes: some actions that are considered bad are actually good.

How did she get to her conclusion? This way: there are actions that have no favorable consequence(It is a necessary assumption in Pat's argument), and therefore are considered bad by our society (This is where she makes the reasoning error) , and she goes on that because some good actions also have no favorable consequences then some of those actions that society lables bad are actually good (Here she makes another reasoning error that is to throw us off).

[WaltGrace1983]

Ted says that an action is good only if it has favorable consequences. That means favorable consequences are a necessary condition of good actions. But then he concludes that, because some actions considered to be bad have favorable consequences, they are really good actions. Well, that would be true if favorable consequences were a sufficient condition of good actions, rather than a necessary one.

I'm a bit confused about this part. I diagrammed this and feel like there isn't a logical error.

Premise 1: "Some actions that are bad have favorable consequences"
Bad ---some---> favorable

Premise 2: "An action is good only if it has fav consequences"
Good ------> favorable

Conclusion: "Some actions are bad are actually good"
Bad ---some---> good

Since Premise 1 is a "some statement" and so can be reversed to say "favorable ---some---> bad," can't you link this with Premise 2 to say:
Good ----> favorable ---some---> bad

Therefore, Good ---some---> bad. And (correctly reversed again since this is another some statement), you can say bad ---some ---> good, which is exactly what Terry says.

Pat does the same thing and reverses a some statement to link the conditionals together.

Can someone please explain where I went wrong?

What you are doing wrong is assuming an overlap, which is basically what the argument is doing. I'll map this out (and I use ":" to mean "some")

Terry

B : FC
~B → FC
=====
B : ~B

Pat:

~B : ~FC
B → ~FC
=====
B : ~B

Two things can be directly opposite each other (like ~Bad and Bad) and still have the same consequences. However, that doesn't mean that there is a contradiction!

Basically, here is what is going on:

Terry

B : FC
FC → ~B
=====
B : ~B

Pat:

~B : ~FC
~FC → B
=====
B : ~B

Terry and Pat are both assuming a SUFFICIENT CONDITION, despite the fact that what they are saying is NECESSARY CONDITIONAL.

(A) no property (FC/~FC) is actually distinguishing them. They have the same property!

(B) "Most" to "all" flaw is not being done here.

(C) "One case" to "Every case" flaw is not happening here.

(E) Not assumed. While the certain property IS shared by the two types of action, the author is not assuming that this is the ONLY property distinguishing them.

[plaouplezm]

I was still confused looking at this problem and the only way I could come to understand it was by combining formal with conditional logic.

action bad <---s----> Favorable <--------- action good

using formal logic you can go right to left and say

action bad <---s----> action good

using action good as the sufficient but you cannot use action bad as sufficient so in other words you cannot go left to right using the formal logic.

Again, not 100% but if heard of crazier things. This problem showed up in a Cambridge Formal Logic packet as well

[donghai819]

It was quite clear for me that T and P have sufficient/ necessary assumption flaws, though it was very unlikely for me to point exactly what the flaws are under the time pressure. LSAT Geeks, my question is: if the feeling that there must be some sufficient/ necessary flaws involved in the argument could be a reasonable grounds to quickly rule out question choices without mention sufficient/ necessary assumption flaws?

Thank you very much.

[tommywallach]

Yep. I mean, it's possible you're wrong, but any time you try to apply some sort of trick, there's a small possibility you'll be wrong. But still, I use the same logic you're asking about all the time. Sometimes, you just KNOW the right answer needs to be mentioning some sort of language (causality, or correlation, or necessary or sufficient assumptions).

-t

[roflcoptersoisoi]

This seems like a time trap question. It's towards the end of the section so if you're running short on time you'd be well advised to skip it and return if you have the time.

I had to diagram this out otherwise I don't think I wouldn't have been able to identify the necessary/sufficent flaw.

B some FC
G --> FC
-----------
B some G

This is not a valid argument form, it would be correct if it said instead that

B some FC
FC ---> G
-------------
B some G

So in this instance, author mistakes a necessary condition for a good action to be a sufficient for said action.

G some ~FC
B some ~FC
--------------
B some G


Again this is not a valid argument form. This would be valid if instead he said:

G some ~FC
~FC some B
------------------
G some B

Same flaw. Our answer choice will address this.


(A) Descriptively inaccurate. There is no indication that the property in question is even a distinguishing one, and none of the agents even talk about any of the other potentially distinguishing properties of bad or good actions.
(B) None of them presuppose this, as neither uses faulty extrapolation in their reasoning.
(C) Descriptively inaccurate. They are both speaking specifically about actions in their societies, not all societies.
(D) Bingo
(E) Descriptively inaccurate, none of them mention other actions or their distinguishing characteristics, nor do they take for granted that some of the properties for the good or bad actions are distinguishing ones.