sufficient and necessary conditions in this sentence: Forum

[naillsat]

the fibers of green cotton only recently became commercially available when a long-fibred variety that can be spun by machine was finally bred.

in this above sentence, I think the word "when" introduces the sufficient condition (according to LR Bible) and "only" introduces the necessary condition, so the logic condition is: long-fibred variety that can be spun by machine (sufficient) --> green cotton became commercially available.

However, my this understanding is apparently wrong based on the answer. So I wonder whether my understanding of the logical is a mistaken reversal?

[PigBodine]

the fibers of green cotton only recently became commercially available when a long-fibred variety that can be spun by machine was finally bred.

in this above sentence, I think the word "when" introduces the sufficient condition (according to LR Bible) and "only" introduces the necessary condition, so the logic condition is: long-fibred variety that can be spun by machine (sufficient) --> green cotton became commercially available.

However, my this understanding is apparently wrong based on the answer. So I wonder whether my understanding of the logical is a mistaken reversal?

the long-fibered variety isn't enough to be sufficient. it's hinting that it might be necessary, but it's not quite there. for it to be sufficient, it'd have to be the case that, given a long-fibered variety being bred, fibers of green cotton would be the inevitable result. we don't have enough evidence to say that.

the word 'only' doesn't have anything to do with necessary-ness or sufficiency in this question, though. it sounds like you might be taking some of the examples in the LR bible a little too seriously -- these words can introduce certain types of conditions, but they don't always have to. I don't remember this question at all in terms of what the answer was, or what kind of deduction it was looking for, but I'm guessing it was asking you to be able to understand that the cloth being machine-spun isn't a necessary condition for green cotton -- it's just trying to point you that way with some leading langauge.

[JamMasterJ]

this is correlation, not sufficient and necessary.

[PigBodine]

whether or not this question was specifically asking us to determine necessary-ness or sufficiency, I think it's still a really teachable example of something that might look necessary on first blush, but isn't. that's the kind of distinction that a person needs to do pretty reliably to hit 170, imo

[tennisking88]

this is correlation, not sufficient and necessary.

[kaiser]

.

[tennisking88]

Not every time you see an "only" should you assume there is sufficiency or necessity

[kaiser]

Idk guys, the phrasing of the sentence makes it sound like the green cotton fiber wasn't possible before the long-fiber variety was spun.

The "only" in the sentence can serve a purpose if you look at the context of the phrase. It says "...only recently became available when...". You can boil this down to "only when", which most certainly links the 2 clauses in a sufficient/necessary relationship.

[JamMasterJ]

Idk guys, the phrasing of the sentence makes it sound like the green cotton fiber wasn't possible before the long-fiber variety was spun.

The "only" in the sentence can serve a purpose if you look at the context of the phrase. It says "...only recently became available when...". You can boil this down to "only when", which most certainly links the 2 clauses in a sufficient/necessary relationship.

no, there could have been another way for this to happen

[PigBodine]

Idk guys, the phrasing of the sentence makes it sound like the green cotton fiber wasn't possible before the long-fiber variety was spun.

not quite -- it's a finer distinction than that. it said that it became available when a certain kind of machine was made. maybe there's a second machine that howard hughes keeps locked in a filing cabinet. maybe there's a genie that can grant wishes to turn certain kinds of fiber into green cotton. it's really close to being necessary, but isn't. there's not enough evidence that there's no other way to produce the material -- just that it didn't actually occur until the machine was invented.

[tennisking88]

Idk guys, the phrasing of the sentence makes it sound like the green cotton fiber wasn't possible before the long-fiber variety was spun.

The "only" in the sentence can serve a purpose if you look at the context of the phrase. It says "...only recently became available when...". You can boil this down to "only when", which most certainly links the 2 clauses in a sufficient/necessary relationship.

I don't see causation here. Just because one happened before the other doesn't mean one (long-fiber variety) caused the other (green cotton fiber). Capisce?

[kaiser]

Let me posit a hypothetical that hopefully parallels this sentence:

"The technology to build a 3D TV only recently became available when the supertechnochip was finally created"

The only change I inserted is the extent to which the factors seem "related" to one another in the level of necessity of the chip (the long-fibered variety) to the TV (green cotton). I have NOT changed the wording of the conditional relationship. Yet would you agree that my hypothetical sentence is conditional? Or would you say it has the same "flaw" as OP's sentence?

[kaiser]

Idk guys, the phrasing of the sentence makes it sound like the green cotton fiber wasn't possible before the long-fiber variety was spun.

The "only" in the sentence can serve a purpose if you look at the context of the phrase. It says "...only recently became available when...". You can boil this down to "only when", which most certainly links the 2 clauses in a sufficient/necessary relationship.

I don't see causation here. Just because one happened before the other doesn't mean one (long-fiber variety) caused the other (green cotton fiber). Capisce?

Conditional reasoning is not causation. Conditional reasoning is correlation (i.e. "I got an A+ therefore I studied" is not a causal relationship, it is merely indicating a correlation between 2 factors, which is all conditional reasoning necessarily indicates)

[JamMasterJ]

Let me posit a hypothetical that hopefully parallels this sentence:

"The technology to build a 3D TV only recently became available when the supertechnochip was finally created"

The only change I inserted is the extent to which the factors seem "related" to one another in the level of necessity of the chip (the long-fibered variety) to the TV (green cotton). I have NOT changed the wording of the conditional relationship. Yet would you agree that my hypothetical sentence is conditional? Or would you say it has the same "flaw" as OP's sentence?

theoretically, something other than the techochip could have led to the 3D TV and the technochip also may not be the reason that the 3D TV was able to be created, making this statement neither sufficient nor necessary. Same flaw as in the OP

[kaiser]

Let me posit a hypothetical that hopefully parallels this sentence:

"The technology to build a 3D TV only recently became available when the supertechnochip was finally created"

The only change I inserted is the extent to which the factors seem "related" to one another in the level of necessity of the chip (the long-fibered variety) to the TV (green cotton). I have NOT changed the wording of the conditional relationship. Yet would you agree that my hypothetical sentence is conditional? Or would you say it has the same "flaw" as OP's sentence?

theoretically, something other than the techochip could have led to the 3D TV and the technochip also may not be the reason that the 3D TV was able to be created, making this statement neither sufficient nor necessary. Same flaw as in the OP

I see the distinction you are making, and why I guess it technically has to be made. The word "when" really screws the whole thing up.

[PigBodine]

Let me posit a hypothetical that hopefully parallels this sentence:

"The technology to build a 3D TV only recently became available when the supertechnochip was finally created"

The only change I inserted is the extent to which the factors seem "related" to one another in the level of necessity of the chip (the long-fibered variety) to the TV (green cotton). I have NOT changed the wording of the conditional relationship. Yet would you agree that my hypothetical sentence is conditional? Or would you say it has the same "flaw" as OP's sentence?

I think a word like 'recently' has too much of a temporal aspect to it to indicate necessity. to do that, you'd need a more absolute phrase, like 'the technology to build a 3D TV would only be possible with the invention of a new kind of chip'. then 'new chip' is necessary for '3D TV'. with a word like 'recently,' you're focusing in on one case, and the statement isn't absolute. you're allowing for the possibility of other chips to serve the same role.

[JamMasterJ]

Let me posit a hypothetical that hopefully parallels this sentence:

"The technology to build a 3D TV only recently became available when the supertechnochip was finally created"

The only change I inserted is the extent to which the factors seem "related" to one another in the level of necessity of the chip (the long-fibered variety) to the TV (green cotton). I have NOT changed the wording of the conditional relationship. Yet would you agree that my hypothetical sentence is conditional? Or would you say it has the same "flaw" as OP's sentence?

theoretically, something other than the techochip could have led to the 3D TV and the technochip also may not be the reason that the 3D TV was able to be created, making this statement neither sufficient nor necessary. Same flaw as in the OP

I see the distinction you are making, and why I guess it technically has to be made. The word "when" really screws the whole thing up.

yeah, everyday reasoning would dictate that causality is most likely present, but in LSAT-strict logic, this isn't the case

[tennisking88]

the fibers of green cotton only recently became commercially available when a long-fibred variety that can be spun by machine was finally bred.

The condition here is:

When a long fibered variety...was bred => the fiberts of green cotton only recently became available.

Does the "only" in that clause seem particularly relevant? Sure as heck doesn't to me.

[PigBodine]

it's 100% extraneous

[naillsat]

so you guys dont think it is conditional or causal relations? i am confused

[JamMasterJ]

so you gus dont think it is conditional or causal relations? i am confused

it is not

[tennisking88]

No, and the LSAT will very rarely test you on something as convoluted as that

[kaiser]

OP, where is this sentence from? Something just doesn't seem right to me, and I would like to look it up myself if possible.

[naillsat]

to make the question source clear, i was referringto pt 24 S3 #11. the correctanswer in B seems like a contrapositive answer to me : cotton that can be spun only by hand ( no machine ) _-----> not commercially viable.

this is why i said in my first post that the correct conditional is commercially available --> fibers can be spun by machine was bred

[kaiser]

So I guess I wasn't crazy because thats the exact conditional I was trying to argue (that being green cotton fiber commercially available --> long-fiber variety spun by machine bred)