If there's a logic chain, must it be connected? Forum

[speedwagon]

This is actually more of an overall strategy q than a specific question q...

The stimulus for the text lays out: if s, i. If f, s. Then there's an unrelated statement that isn't involved. It's a MBT.

The correct answer is essentially if not i, not f, which is a correct contrapositive in the logical chain.

However, I don't see anything in the stimulus that permits the inference of hooking them together, and therefore I didn't. I imagine this as similar to LG thinking: just because G is before H and F is before H doesn't say anything about G and F.

Clearly this is wrong in the case of this q. Is this an error overall? Ie, if there is a logic chain that could be hooked up, must it always be hooked up?

Thanks a ton.

[maybeman]

If a chain of variables can be hooked, you should definitely think about it. That doesn't mean some implied relationship will always be the AC though. The logical chain in your LR example is very different from the one you use in the LG example, so I'm confused. Just because the stim doesn't expressly tell you that you can hook variables together doesn't mean you can't. In fact, if you don't hook logically connected phrases things up in LR, you're probably missing half the section. Your LG example is correct -- F and G have no relationship. But that seems irrelevant to the question you're confused about in LR.. Not really sure how to help ya. Look up an explanation?

[speedwagon]

If a chain of variables can be hooked, you should definitely think about it. That doesn't mean some implied relationship will always be the AC though. The logical chain in your LR example is very different from the one you use in the LG example, so I'm confused. Just because the stim doesn't expressly tell you that you can hook variables together doesn't mean you can't. In fact, if you don't hook logically connected phrases things up in LR, you're probably missing half the section. Your LG example is correct -- F and G have no relationship. But that seems irrelevant to the question you're confused about in LR.. Not really sure how to help ya. Look up an explanation?

I appreciate it. That metaphor is wrong and I think it has something to do with why I am missing this q. It mostly has to do with if you can hook em up, must it be correct to do so - or really, if you do, will it ding you sometimes. It sounds like the answer is it might be kosher and is likely worth considering. What the LSAT considers an appropriate assumption and what it insists is off limits is really mystifying.

[maybeman]

Anything that can be appropriately connected with conditional logic will never make you miss a point. It may take up time unnecessarily, but the lsat is always right, and they don't screw up logic.. Just a guess, but I think your issue is with conditional logic itself. I'd review your fundamentals

[Deardevil]

Think about it.

If cats are soft, then marbles are hard.
If marbles are hard, then dogs are the best pets.
When cats are soft, what do we know? Marbles are hard.
And when that is the case, we also know dogs must be the best pets.

G and F being in front of H is not the same because there is no condition that is BOTH sufficient and necessary.
Only when there is a condition that satisfies sufficiency and necessity can you be sure that linkage is a possibility.

A -> B -> C -> D comes up on the test,
so it is best to link it all up and not dwell on one or two conditions because the ACs can play around with all of them.

[kindofcanuck]

This is actually more of an overall strategy q than a specific question q...

The stimulus for the text lays out: if s, i. If f, s. Then there's an unrelated statement that isn't involved. It's a MBT.

The correct answer is essentially if not i, not f, which is a correct contrapositive in the logical chain.

However, I don't see anything in the stimulus that permits the inference of hooking them together, and therefore I didn't. I imagine this as similar to LG thinking: just because G is before H and F is before H doesn't say anything about G and F.

Clearly this is wrong in the case of this q. Is this an error overall? Ie, if there is a logic chain that could be hooked up, must it always be hooked up?

Thanks a ton.

If the stim or game says: "If S then I. If F, then S", then they're giving you all you need to know that "if F then S then I, and if not I, neither S, nor F".

If the stim/game tells you G before H, and F before H, then you know neither F nor G come after H, and you can diagram as "G/F ... H"