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Hi,
I am practicing turning the kind of colloquial English sentences on the LSAT into strict logical statements. For example, take the following sentence:
All that is needed for the forces of evil to succeed is for enough good men to remain silent.
I would translate this logically as:
enough good men to remain silent --> forces of evil to succeed
I'm reading "All that is needed is" to signify that the predicate that follows will be a sufficient condition. Here are four more examples:
- The only thing necessary for the triumph of evil is for good men to do nothing.
- In order for ‘evil’ to prevail, all that need happen is for ‘good’ people to do nothing.
- The surest way for evil to prevail is for good men to do nothing.
- All it takes for Evil to prevail in this world is for enough good men to do nothing.
I suspect that the predicate in each case defines a sufficient condition. What do you think?
Thanks,
Stephanie
Premise 1: "the fact that all that would be needed to make money disappear would be a universal loss of believe in it."
universal loss of belief --> money disappears
Premise 2: "fluctuations are the result of mere beliefs of investors"
investors' beliefs --> fluctuations (i.e. money disappears and comes back)
From the two premises:
universal loss of belief --> money disappears
investors' beliefs --> money disappears
We can say: Regardless of people's beliefs, money disappears. If everyone loses belief (universal loss of belief), it disappears. If they do believe (like investors), it fluctuates, temporarily disappearing. Thus, we can accept "Money disappears" as a fact:
A --> B
Not A --> B
-----------
Thus: B
Now the editorialist's conclusion is: Money does not exist.
So the sufficient assumption the stem requests is:
money disappears --> money does not exist
Notice, this leads to the contrapositive:
money exists --> money does not disappear
To reiterate, in plain English: If money exists, then money doesn't disappear, even if people do not believe it.
Compare answer A: "Anything that exists would continue to exist even if everyone were to step believing in it."
This answer sufficiently guarantees the arguments validity (since "anything" would obviously include money.)
The key here is the phrase "even if". "A even if B" means "A regardless of B" or "A whether or not B". This reiterates our inference above: (A --> B) and (Not A --> B), thus B.