Self-paced
Politician: Now that we are finally cleaning up the industrial pollution in the bay, we must start making the bay more accessible to the public for recreational purposes.
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Flawed Argument: Denying the Sufficient Condition
The politician, in responding to the reporter, concludes that if we give the public access to the bay, the bay will not be polluted. How do we know? Because in the past, the public didn't have access to the bay, and the bay got polluted.
P: /public access → polluted
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C: public access → /polluted
Unfortunately for the politician, this argument denies the sufficient condition, a form of sufficient-necessary confusion—in other words, a logical flaw. So our goal is to find another argument which denies a sufficient condition, and then concludes that the necessary condition is also negated.
7.
Which one of the following ████ ███████ █████████ ███ ██████ ███████ ██ █████████ ██ ███ ██████████████ █████ ██ ███ █████████
a
If there had ████ █ ████ ████ ████ ██████ ███ ████ █████ ██ ██████ ████ █████ ██████ █████ ███ ████ ██ ██ ██████ ████ ██████ █████ ████ ███ ████ ████ █ ████ ████ ████ ██████
P1: full moon → unusually high tide
P2: /unusually high tide
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C: /full moon
(A) not only differs from the form of the stimulus, it's a valid argument. By denying the necessary condition, (A) logically concludes that the sufficient condition is denied. To match the stimulus, we're looking for the opposite: an argument that denies the necessary condition.
b
The detective said ████ ███████ █████ ███ █████ █████ ██ ████████ ██ █████████████ ██ ████ █████ ██ ████████ █████ ██████████████ ██ ██ ████ ██ ███ ██████
P1: stole money → spending conspicuously
P2: Jonesspending conspicuously
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C: Jonesstole money
Aside from having two premises and a factual conclusion, where the stimulus has one premise and a conditional conclusion, (B) uses a different flawed argument pattern. This argument affirms the necessary condition, whereas the stimulus denies the sufficient condition.
c
When prisoners convicted ██ ██████████ ███████ ██████ ████ ████ ██ ████████ ████████████ ████████ ██ ███ ███████ ██████████ ██████████ ████████ ██ ███ ███████ ████ ███ ████████ ██ ████ █████████ ███ ███████ ██ ███ ████ ██████ ██████████
P: solitary confinement → increased violence
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C: /solitary confinement → /increased violence
(C) immediately looks promising: like the stimulus, it has a single premise, and a conditional conclusion. And the contents of those elements are also correct. In a match with the stimulus, (C)'s flaw is that it denies the sufficient condition.
d
To get a ██████████ ████████ ███ ████ ████ █ ███████ █████ █████ ██████ ███ ███████ █████ ██ ███ ████ ████ ██████ █ ██████████ ████████
P1: receive driver's license → pass written test
P2: Smithpassed written test
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C: Smithreceived driver's license
Aside from having two premises and a factual conclusion, where the stimulus has one premise and a conditional conclusion, (D) uses a different flawed argument pattern. This argument affirms the necessary condition, whereas the stimulus denies the sufficient condition.
e
In order to ████ ████████ ████ ███ ████ ██ ██████████ ███ ██████████ ██ █████ ██ ██████████ ████████ ████ ███ ████ ██ ████ ███
P: like abstract art → understand abstract art
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C: understand abstract art → like abstract art
(E) has some similarities with the stimulus: it only has a single premise, and a conditional conclusion. However, (E) commits a different form of sufficient-necessary confusion: it simply swaps the two conditions, whereas the stimulus denies the sufficient condition.