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I'm disagreeing with how JY did this because we can't use common sense in MBT nor make up assumptions because we think it makes sense to us. MSS is fine because it's always a 95% certainty and 5% wiggle room for some common sense.
That is invalid because what is a valid argument and what is a sound argument are two different things. In MBT we are focusing if it is valid not if it is sound but JY isn't doing that
His argument goes in the lawgic
Standard committee ---> 6 PM
General assembly ----> 7 pm
6 isn't 7
so 6 ----> /7
Which he gets
SQ ----> 6 ---> /7 ----> /General assembly
The problem is that is not a valid argument. We can't negate assumptions since we are removing alot of presumptions.
I KNOW that 6 isn't 7, but thats not the controversy. The controversy is aligning an assumption against another assumption through negation, which that's not a valid argument.
For all we know in sound arguments, 6 is 7, or 6 does not necessarily contradict 7 (or vice versa)
Why not? Because what if it lasts 5 minutes the assembly. What if the coordinators are so stupid that they do it at the same time. Not common sense but still valid.
Parallel flaw example:
Juan likes tacos
Jake likes cars
Tacos aren’t cars
Therefore Juan —> /Jake
=====================
The lawgic
Juan –> tacos
Jake —> Cars
tacos—-> /cars
Therefore Juan —> Jake
Explanation Video: https://7sage.com/lsat_explanations/lsat-83-section-1-question-18/
Admin Note: Edited title. Please use the format: "PT#.S#.Q# - brief description of the question"
Comments
Juan --> /jake
There are two conditional statements, each of which have contrapositives so I will write the four statements here.
sc has quorum --> ga will begin at 6
ga does not begin at 6 --> sc does not have quorum
ac has quorum --> ga will begin at 7
ga will not begin at 7 --> ac does not have quorum
we can combine these statements:
if the ga begins at 7 that means it does not begin at 6, and according to the contrapositive:
ga does not begin at 6 ---> sc does not have quorum; therefore, if the ga begins at 7 then sc does not have quorum
also, if ga begins at 6 then it does not begin at 7, and according to the second contrapositive, if the ga does not begin at 7 then ac does not have quorum; therefore, if the ga begins at 6 then ac does not have quorum.
This is what AC E says so E is correct.
The argument you give as a parallel example isn't really the same but there is definitely a weird assumption that the General Assembly can't begin twice, once at 6 and again at 7. I remember getting this right and not overthinking that detail at the time, but I don't see any reason for that being guaranteed by the prompt now.
However, E is the only answer choice that makes any sense at all. The rest don't follow logically from anything the prompt says at all.
Maybe the word "begin" implies a single occurrence. Maybe things don't begin twice? They "begin" and later they "resume." If that's true, then 6 implies (not7) and 7 implies (not6), (not6) implies (notStandardsQuorum) and (not7) implies (notAwardsQuorum), so E is logically valid.
It's reasonable to assume the GA can't "begin" at both 6pm and 7pm.
I'm guessing that by "what if it lasts 5 minutes the assembly" you mean "couldn't there be two 5 minute assemblies - one at 6 and one at 7?"
That doesn't work because the argument says "the" general assembly, not "a" general assembly. This implies there is only one, and why would one meeting start at two times?
The stimulus says,
If the stimulus had said, "If the standards committee has a quorom, then by the coordinators schedule the general assembly will begin at 6:00 pm today," this might work. However, the stimulus just says "if quorom, then general assembly at 6".
You have to accept statements in the stimulus as facts.
Another reason this is correct is because, as other posters have said, no other answer makes sense.
Soundness is when an argument is logically valid and factually true.
The can be used for plural and for singular use. It would be quite haughty for LSAT to use it for this one case out of thousands, especially when it is vague for a MBT
I am accepting the premises. We can't make assumptions on what they think they say, just on what they literally said. The only time we can do that comes from resulting from the actions of the premises.
I never got a valid response on why it's 5 minutes one then the other can't
That's because hindsight is 20/20. How are students supposed to know that when they remove it all. It's fine if it was a MSS but not when it's a MBT because it needs to be 100% true from the stimulus alone.
Right but we aren't worried about if it is sound. That was the issue I get because the video says it's "common sense" for us to assume it. I wondering if it's valid
A deductive argument is said to be valid if and only if it takes a form that makes it impossible for the premises to be true and the conclusion nevertheless to be false. Otherwise, a deductive argument is said to be invalid.
A deductive argument is sound if and only if it is both valid, and all of its premises are actually true. Otherwise, a deductive argument is unsound.
I don't understand how you're interpreting "the general assembly" to denote 2 events. Can you explain that part specifically?
Also, I said this in another comment, but your analogy with the tacos and cars cannot be properly established because of relevant differences in the circumstances.
Re-read the stimulus.
The diagramming from your first post (not sure if yours or JY’s, haven’t seen the video) is not correct.
You should have diagrammed it as:
Standard committee -> GA time 6
Awards committee -> GA time 7
The conclusion is that both can’t have quoroms, because the general assembly can’t start at both 6 and 7.
We do bring a bit of factual knowledge into the lsat. We assume that 6 and 7 are times, and we know that two times can’t happen at the same time.
Review any lsat question you got right and you will see there is a bit of “common sense” assumption there.