## Stre/weakening questions

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ltowns1

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### Stre/weakening questions

Hey guys what should I do when I see condtional reasoning on strengthen/weaken questions within the premise but not in the conclusion.. I usually just attack the necessary condition of the conditional statement?

BasilHallward

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### Re: Stre/weakening questions

ltowns1

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### Re: Stre/weakening questions

Ok let me say it this way...when you see that a conditional statement is in the stimulus, and there is no conditional statement in the conclusion, and the condtional pertains to the core of the argument, what would you do? (Regarding specifically strengthen/weaken questions

Jeffort

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### Re: Stre/weakening questions

ltowns1 wrote:Ok let me say it this way...when you see that a conditional statement is in the stimulus, and there is no conditional statement in the conclusion, and the condtional pertains to the core of the argument, what would you do? (Regarding specifically strengthen/weaken questions

You should examine how the elements presented as evidence in premises other than the conditional one and how the elements in the conclusion relate to the elements in the conditional premise in order to figure out how the argument uses the conditional premise in the reasoning of the argument in order to figure out which flaw(s) are being committed. Conditionals can be used in many different ways in various different patterns of reasoning so you really have to examine how it's being used in the context of each argument to pinpoint the flaw(s) of the argument in order to help determine/pre-phrase how to attack or strengthen the argument.

Also keep in mind that arguments containing a conditional premise are not always making a basic conditional reasoning flaw such as invalid reversal or negation or any conditional reasoning flaw at all while others do. That's a big part of the reason why it's important to examine how the conditional premise(s) functions/is being used in the reasoning within the context of the other premises and background information if any.

I think your questions would be clearer if you explain what you mean by saying things like 'attack the necessary condition', it's pretty vague and I'm not exactly sure what you mean by that. Do you mean showing that the sufficient can exist while the purported necessary condition does not?

ltowns1

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Joined: Mon May 26, 2014 1:13 am

### Re: Stre/weakening questions

I think your questions would be clearer if you explain what you mean by saying things like 'attack the necessary condition', it's pretty vague and I'm not exactly sure what you mean by that. Do you mean showing that the sufficient can exist while the purported necessary condition does not?[/quote]

Yep pretty much

ltowns1

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Joined: Mon May 26, 2014 1:13 am

### Re: Stre/weakening questions

Jeffort wrote:
ltowns1 wrote:Ok let me say it this way...when you see that a conditional statement is in the stimulus, and there is no conditional statement in the conclusion, and the condtional pertains to the core of the argument, what would you do? (Regarding specifically strengthen/weaken questions

You should examine how the elements presented as evidence in premises other than the conditional one and how the elements in the conclusion relate to the elements in the conditional premise in order to figure out how the argument uses the conditional premise in the reasoning of the argument in order to figure out which flaw(s) are being committed. Conditionals can be used in many different ways in various different patterns of reasoning so you really have to examine how it's being used in the context of each argument to pinpoint the flaw(s) of the argument in order to help determine/pre-phrase how to attack or strengthen the argument.

Also keep in mind that arguments containing a conditional premise are not always making a basic conditional reasoning flaw such as invalid reversal or negation or any conditional reasoning flaw at all while others do. That's a big part of the reason why it's important to examine how the conditional premise(s) functions/is being used in the reasoning within the context of the other premises and background information if any.

I think your questions would be clearer if you explain what you mean by saying things like 'attack the necessary condition', it's pretty vague and I'm not exactly sure what you mean by that. Do you mean showing that the sufficient can exist while the purported necessary condition does not?

Yep,that's pretty much what I mean.i recognize you should examine the logic first, but once you figure out that the condtional relationship is being tested what then should you do.

Jeffort

Posts: 1888
Joined: Wed Jun 18, 2008 4:43 pm

### Re: Stre/weakening questions

ltowns1 wrote:
Jeffort wrote:
ltowns1 wrote:Ok let me say it this way...when you see that a conditional statement is in the stimulus, and there is no conditional statement in the conclusion, and the condtional pertains to the core of the argument, what would you do? (Regarding specifically strengthen/weaken questions

You should examine how the elements presented as evidence in premises other than the conditional one and how the elements in the conclusion relate to the elements in the conditional premise in order to figure out how the argument uses the conditional premise in the reasoning of the argument in order to figure out which flaw(s) are being committed. Conditionals can be used in many different ways in various different patterns of reasoning so you really have to examine how it's being used in the context of each argument to pinpoint the flaw(s) of the argument in order to help determine/pre-phrase how to attack or strengthen the argument.

Also keep in mind that arguments containing a conditional premise are not always making a basic conditional reasoning flaw such as invalid reversal or negation or any conditional reasoning flaw at all while others do. That's a big part of the reason why it's important to examine how the conditional premise(s) functions/is being used in the reasoning within the context of the other premises and background information if any.

I think your questions would be clearer if you explain what you mean by saying things like 'attack the necessary condition', it's pretty vague and I'm not exactly sure what you mean by that. Do you mean showing that the sufficient can exist while the purported necessary condition does not?

Yep,that's pretty much what I mean.i recognize you should examine the logic first, but once you figure out that the condtional relationship is being tested what then should you do.

Can you post a few LR str & wkn questions (just the PT Q reference info, not the actual questions themselves obviously) with a conditional premise that you're having difficulty with so we can discuss this more specifically with actual arguments rather than in the abstract?

I'm still confused by your question, in part because 'attacking the necessary condition' of a conditional premise used in an argument would be a way of weakening/proving that the conditional premise/conditional relationship itself is false, thereby just contradicting an explicit premise of the argument rather than weakening the reasoning of the argument.

Attacking the necessary condition by showing that the sufficient condition can be true while the purported necessary condition is false is a good way to weaken an argument that asserts a conditional conclusion, but you're asking about arguments that contain a conditional premise but not a conditional conclusion. Remember that with LR arguments the ground rules are that you have to accept all the explicit premises as true, so attacking the validity of an explicitly stated conditional premise is not a viable way to weaken the reasoning of an argument (unless the conditional premise/relationship is just presented as being a claim/belief/opinion rather than a factual conditional premise/relationship) since you'd just be proving that an explicit premise of the argument is false/contradicting an explicit premise rather than undermining the reasoning by weakening an assumption of the argument.

ltowns1

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Joined: Mon May 26, 2014 1:13 am

### Re: Stre/weakening questions

Jeffort wrote:
ltowns1 wrote:
Jeffort wrote:
ltowns1 wrote:Ok let me say it this way...when you see that a conditional statement is in the stimulus, and there is no conditional statement in the conclusion, and the condtional pertains to the core of the argument, what would you do? (Regarding specifically strengthen/weaken questions

You should examine how the elements presented as evidence in premises other than the conditional one and how the elements in the conclusion relate to the elements in the conditional premise in order to figure out how the argument uses the conditional premise in the reasoning of the argument in order to figure out which flaw(s) are being committed. Conditionals can be used in many different ways in various different patterns of reasoning so you really have to examine how it's being used in the context of each argument to pinpoint the flaw(s) of the argument in order to help determine/pre-phrase how to attack or strengthen the argument.

Also keep in mind that arguments containing a conditional premise are not always making a basic conditional reasoning flaw such as invalid reversal or negation or any conditional reasoning flaw at all while others do. That's a big part of the reason why it's important to examine how the conditional premise(s) functions/is being used in the reasoning within the context of the other premises and background information if any.

I think your questions would be clearer if you explain what you mean by saying things like 'attack the necessary condition', it's pretty vague and I'm not exactly sure what you mean by that. Do you mean showing that the sufficient can exist while the purported necessary condition does not?

Yep,that's pretty much what I mean.i recognize you should examine the logic first, but once you figure out that the condtional relationship is being tested what then should you do.

Can you post a few LR str & wkn questions (just the PT Q reference info, not the actual questions themselves obviously) with a conditional premise that you're having difficulty with so we can discuss this more specifically with actual arguments rather than in the abstract?

I'm still confused by your question, in part because 'attacking the necessary condition' of a conditional premise used in an argument would be a way of weakening/proving that the conditional premise/conditional relationship itself is false, thereby just contradicting an explicit premise of the argument rather than weakening the reasoning of the argument.

Attacking the necessary condition by showing that the sufficient condition can be true while the purported necessary condition is false is a good way to weaken an argument that asserts a conditional conclusion, but you're asking about arguments that contain a conditional premise but not a conditional conclusion. Remember that with LR arguments the ground rules are that you have to accept all the explicit premises as true, so attacking the validity of an explicitly stated conditional premise is not a viable way to weaken the reasoning of an argument (unless the conditional premise/relationship is just presented as being a claim/belief/opinion rather than a factual conditional premise/relationship) since you'd just be proving that an explicit premise of the argument is false/contradicting an explicit premise rather than undermining the reasoning by weakening an assumption of the argument.

Ok...forget "attacking the premise" lol. It's not that I'm really having trouble with it, but I'm not clear on the strategy to take(if that makes sense) I need to have a better understanding. Anyways..PT 33 section 1,#20. While I'm at it could you show me the approach to take on the infamous flower question on PT 31, section 1 #19. (I know it contains a conditional conclusion, but I figure while I have your highly demanded attention, I might as well use you to full effect lol.)

Christine (MLSAT)

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Joined: Fri Nov 22, 2013 3:41 pm

### Re: Stre/weakening questions

I'm really curious to hear Jeffort's thoughts on these, but I'll give you my take - I kind of love the flower question, to be honest. Whenever you have a conditional premise, there are two thoughts that should pop up: 1) do we know that this conditional was actually triggered? and 2) even if it was, what assumptions are required even after you have the result of the conditional in play?

I'll walk through my internal monologue when I read a question like the flowers one - because there are a series of conditional-premises and then fact-premises, I'm sorting out how those relate to one another as I go - this way, when I get to the conclusion and see what crazy thing they're claiming, I'm in a better position to compare that to what one could validly conclude.

Conditional premise: If sender knows Drew --> know Drew prefers violets
Okay, so either sender doesn't know Drew or sender is a jerk who doesn't care what Drew prefers
Conditional premise: If sender doesn't know Drew --> card
Fact premise: no card
Well, that seems to kill the possibility that the sender doesn't know Drew. I guess sender is a jerk?
Conclusion: So, florist screwed up.
Oh, I didn't even think about the possibility that the florist screwed up. Sure, that's possible - but it's still possible the sender is a jerk. That would totally weaken this argument.

As for the cave-paintings-picture-menu question, I'd work through the same essential possibilities - maybe the conditional wasn't tripped; even if it was, what else does the argument assume?

1) The argument assumes that conditional was actually triggered - if it wasn't (i.e., if there was no 'long journey'), then who knows what they ate. (E)
2) The argument assumes, once the conditional is triggered and sea animals are being eaten, that those sea animals were a significant enough part of the overall diet to grant them a place in the cave-painting-picture-menu. The more they ate of other things, the less significant the sea animals could have been. (A) and (D).
3) The argument assumes that just because there are no sea animals pics now, that there never were. (B)

All in all, conditional-premises are not so different from fact-premises. If you knew the conditional had been triggered, then you'd just treat the result as a fact, and then be looking for what additional assumptions the argument is making past that fact. The only substantive difference is that you also have to consider the fact that you may not know for certain the conditional has actually been triggered.

ltowns1

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### Re: Stre/weakening questions

Christine (MLSAT) wrote:
Conditional premise: If sender knows Drew --> know Drew prefers violets
Okay, so either sender doesn't know Drew or sender is a jerk who doesn't care what Drew prefers
Conditional premise: If sender doesn't know Drew --> card
Fact premise: no card
Well, that seems to kill the possibility that the sender doesn't know Drew. I guess sender is a jerk?
Conclusion: So, florist screwed up.
Oh, I didn't even think about the possibility that the florist screwed up. Sure, that's possible - but it's still possible the sender is a jerk. That would totally weaken this argument.

This is essentially what I mean by saying "attack the premise"..what Christine just did. Seems to me she took the first conditional premise, saw if it triggered, and concluded that it did not. Once she established that the contrapositive of the second condtional premise triggered, she analyzed the conditional of the first, and concluded that the best way to attack the argument was to focus on the necessary condtion of the first.(sender knows drew---> sender knows he prefers violets)

Christine (MLSAT)

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### Re: Stre/weakening questions

ltowns1 wrote:This is essentially what I mean by saying "attack the premise"..what Christine just did. Seems to me she took the first conditional premise, saw if it triggered, and concluded that it did not. Once she established that the contrapositive of the second condtional premise triggered, she analyzed the conditional of the first, and concluded that the best way to attack the argument was to focus on the necessary condtion of the first.(sender knows drew---> sender knows he prefers violets)

Careful though - I'm not "attacking" that premise - I'm also not "attacking" the necessary part of the conditional. If the first conditional were triggered, then that would mean that the necessary part of the conditional is a fact: the sender would know that Drew prefers violets. I'm not going to try to undermine that idea, I'm going to figure out what that means for the argument if that fact is in play.

IF that first conditional had been fully triggered (I must point out that it actually wasn't, here) a simplified version of the argument would be:
Premise: Sender knows that Drew prefers violets to roses, and yet Drew received roses.
Conclusion: Florist must have screwed up.
Assumption. That sender would not have intentionally sent something Drew does not prefer.

ltowns1

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### Re: Stre/weakening questions

Christine (MLSAT) wrote:
ltowns1 wrote:This is essentially what I mean by saying "attack the premise"..what Christine just did. Seems to me she took the first conditional premise, saw if it triggered, and concluded that it did not. Once she established that the contrapositive of the second condtional premise triggered, she analyzed the conditional of the first, and concluded that the best way to attack the argument was to focus on the necessary condtion of the first.(sender knows drew---> sender knows he prefers violets)

Careful though - I'm not "attacking" that premise - I'm also not "attacking" the necessary part of the conditional. If the first conditional were triggered, then that would mean that the necessary part of the conditional is a fact: the sender would know that Drew prefers violets. I'm not going to try to undermine that idea, I'm going to figure out what that means for the argument if that fact is in play.

IF that first conditional had been fully triggered (I must point out that it actually wasn't, here) a simplified version of the argument would be:
Premise: Sender knows that Drew prefers violets to roses, and yet Drew received roses.
Conclusion: Florist must have screwed up.
Assumption. That sender would not have intentionally sent something Drew does not prefer.

But I guess that's what I'm saying, it seems that because the first condtional was not triggered, that was the part of the argument you focused on. From there was it that you just looked at the logic and figured out what part of the condtiontional needed to be analyzed from the conclusion??

Jeffort

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Joined: Wed Jun 18, 2008 4:43 pm

### Re: Stre/weakening questions

ltowns1 wrote:
Christine (MLSAT) wrote:
ltowns1 wrote:This is essentially what I mean by saying "attack the premise"..what Christine just did. Seems to me she took the first conditional premise, saw if it triggered, and concluded that it did not. Once she established that the contrapositive of the second condtional premise triggered, she analyzed the conditional of the first, and concluded that the best way to attack the argument was to focus on the necessary condtion of the first.(sender knows drew---> sender knows he prefers violets)

Careful though - I'm not "attacking" that premise - I'm also not "attacking" the necessary part of the conditional. If the first conditional were triggered, then that would mean that the necessary part of the conditional is a fact: the sender would know that Drew prefers violets. I'm not going to try to undermine that idea, I'm going to figure out what that means for the argument if that fact is in play.

IF that first conditional had been fully triggered (I must point out that it actually wasn't, here) a simplified version of the argument would be:
Premise: Sender knows that Drew prefers violets to roses, and yet Drew received roses.
Conclusion: Florist must have screwed up.
Assumption. That sender would not have intentionally sent something Drew does not prefer.

But I guess that's what I'm saying, it seems that because the first condtional was not triggered, that was the part of the argument you focused on. From there was it that you just looked at the logic and figured out what part of the condtiontional needed to be analyzed from the conclusion??

You need to analyze all of it in order to figure out which parts of the reasoning if any are valid in order to home in on and identify which part(s) of the reasoning are flawed.

Christine's breakdowns of the questions are pretty much the same as how I'd explain both those questions. The only exception I have is with the flowers question and whether the first conditional is triggered (person knows Drew well). I believe it is due to the application of a later fact to the second conditional. Since a card wasn't received, applying that fact to the second conditional establishes as fact through the contrapositive that the flowers were sent by somebody that does know Drew well. The two conditionals are an exclusive either or set in the argument since knows him well or not is a binary issue and the argument includes 'on the other hand' to establish the either/or between the conditionals.

ltowns, I might be wrong but it seems like you're kinda looking for a 'one size fit's all' thing to look for or a single specific formula to apply to all str and wkn Q's with conditionals in terms of what specific task the correct answer must logically achieve or which premise(s) and/or elements to prioritize. If that's the case, it varies from question to question based on which specific flawed method(s) of reasoning the argument uses.

A simple way to describe the process we're discusses that Christine applied to explain the proper analysis of the two questions is that when presented with any conditional premises in an argument, just treat them like logic game conditional rules and then fact check the rest of the premises and reasoning to determine the set of facts you have to apply to the conditional premises.

When an argument applies a conditional premise logically, like it did with conditional #2 in the flowers question applying the contrapositive, once you figure that out through analysis you then know that the flaw(s) in the argument lie elsewhere with something else in the reasoning so you shift your attention and analysis to the other premise(s).

Like I said above, arguments use conditionals in various ways, sometimes in logically valid ways and other times flawed ways like invalid reversal or negation. You just figure out what facts are established by the evidence, apply whatever elements you know are true or false to the conditional premise(s) to determine what if any inferences can be validly drawn, then compare to what the argument concludes from them if anything. If there's a basic conditional flaw like invalid reversal or negation, then you've found a flaw in the reasoning and know it's important to focus on.

The main point we're trying to make is that you just have to examine how the facts are applied to the conditionals and everything else in the reasoning to sort out which parts if any are valid to isolate the flawed assumption(s)/flawed reasoning. The specific type of flaw(s)/assumption(s) committed by the argument are what determines which specific logical task/relationship(s) are viable to str or wkn each individual argument.

It sounds like you're thinking about and doing a lot of the same things we're talking about but just describing it with wording that's a bit confusing and inaccurate with the attacking specific elements wording you've been using.

The flowers question doesn't contain a conditional flaw, but you have to analyze the conditionals and facts to figure that out. Part of why they are there is to make the question more complex to analyze by obfuscating the flaw and inviting people to overly focus on the conditional logic trying to find a flaw with it while the clock ticks and they don't realize the flaw lies elsewhere. The flaw is the assumption Christine described, the argument just assumes that somebody that knows drew well would do what they know would please him/her and not be a jerk that doesn't send him/her the type of flowers they know (s)he? prefers.

Another fairly complex one to look at is PT29 S1 Q22, strengthen with a principle. It has multiple conditionals too with relationships between them that are similar in some structural ways but different in other ways than the flowers question with how the conditionals function in the reasoning, so the available ways to logically strengthen the argument are different due to the different roles the conditionals play in the overall reasoning pattern of the argument used to arrive at the conclusion.

Whenever there's at least one conditional premise in an argument, like Christine said, task #1 is inspect to see whether it is triggered by any facts given in or that you can infer from the premises. If so you examine how the conditionals are applied to figure out determine if there's a conditional flaw or not with the ultimate goal of the analysis being to determine which flaw(s)/assumptions the argument contains.

ltowns1

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Joined: Mon May 26, 2014 1:13 am

### Re: Stre/weakening questions

ltowns, I might be wrong but it seems like you're kinda looking for a 'one size fit's all' thing to look for or a single specific formula to apply to all str and wkn Q's with conditionals in terms of what specific task the correct answer must logically achieve or which premise(s) and/or elements to prioritize. If that's the case, it varies from question to question based on which specific flawed method(s) of reasoning the argument uses.
It sounds like you're thinking about and doing a lot of the same things we're talking about but just describing it with wording that's a bit confusing and inaccurate with the attacking specific elements wording you've been

I'd say this is pretty accurate lol..thanks! You guys are two of the smartest people up here,I appreciate you guys taking the time to explain these questions to me. Thank you!

farman

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Joined: Mon Oct 07, 2013 9:56 am

### Re: Stre/weakening questions

I'm no genius but I rarely ever map out conditional logic on a +/- question unless I'm really having a hard time grasping it, like it's really abstract (which tends to happen more with SA questions). Your best bet is to try and find a flaw or multiple flaws in the argument and try to capitalize on them in the answer choices. It doesn't always work, but it does enough of the time that you should do it.