Summarize Argument
The politician concludes that installing new signs is a colossal waste of time and money. This is because no one is complaining about the current signs.
Notable Assumptions
The politician assumes that replacing the current signs is only justified if people have complained about those signs. This means the politician doesn’t believe there’s any other good reason—specifically a reason that doesn’t have to do with public opinion—to replace the signs.
A
What features of the new street signs improve the readability of the signs?
We don’t care what specific features of the new signs improve readability. We need to know whether they’re a colossal waste of money since no one is complaining about the current signs.
B
Are the new street signs considerably more expensive to manufacture than the current street signs were?
We’re not comparing the relative cost of the signs. We care about whether replacing the current signs constitutes a colossal waste of money, which we have no reason to believe has anything to do with how much the signs originally cost to manufacture.
C
What percentage of its street signs does the city replace annually in the course of ordinary maintenance?
If the city replaces many signs throughout the year in the course ordinary maintenance, then the city may actually be saving money by commissioning the signs to be replaced in a single project. If not, then the city seems to just be replacing well-functioning signs.
D
Do any other cities plan to replace their street signs with signs designed for improved readability?
We’re not interested in other cities. Perhaps their signs were recently replaced, or else don’t need to be replaced for the same reason the city in question is choosing to replace its signs.
E
Were experts consulted when the new street signs were designed?
Irrelevant. Even if experts were consulted, we have no idea what their verdict was on replacing the signs.
Summarize Argument: Counter-Position
A book argues that people who are successful in business have always benefited from luck.
The author concludes that the book is wrong. This is based on the fact that success requires hard work.
Identify and Describe Flaw
The author misinterprets the book’s claim as a statement about what’s sufficient for success. The book actually says that luck is necessary for success in business. But the author thinks the book says that luck is sufficient for success. This is what makes the author think that pointing out success requires hard work shows that the book is wrong. The author’s trying to prove that luck alone, without hard work, won’t lead to success. This point, however, is irrelevant to what the book actually said.
A
It mistakes the claim that something is required for a purpose for the claim that it is sufficient for that purpose.
The book claimed that luck is required for business success. But the author interprets that as a claim that luck is sufficient for business success. This confusion is why the author thinks hard work being required for success proves the book wrong.
B
It accepts a view as authoritative without establishing the authority of the source of the view.
The author does not accept any view as authoritative. The author tries to prove the book’s claim is false.
C
It takes for granted in a premise what it is trying to prove in its conclusion.
(C) describes circular reasoning. The author’s conclusion is not restated in a premise.
D
It treats an effect of something as the cause of that thing.
The argument isn’t causal. The author’s trying to disprove the book’s claim by indicating that hard work is required for success. This argument involves sufficiency and necessity, not cause.
E
It attacks the source of an argument rather than attacking the substance of that argument.
There’s no attack on the source of the book’s claim.