Match each flawed argument excerpt on the left with the logical reasoning flaw it most clearly exhibits on the right.
- Every member of the municipal council voted in favor of the transit budget immediately after meeting with union representatives. Therefore, the union representatives must have caused the council members to support the budget.Inferring a causal relationship between two events solely on the basis that one preceded the other.
- The lead engineer argues that the bridge design is structurally unsafe. However, because she was recently passed over for a promotion by the transit authority, her assessment can be safely dismissed.Attempting to refute an argument by citing the potential bias or personal motives of the person making it.
- To qualify for the honors scholarship, an applicant must have a grade point average above 3.8. Since Marcus has a 3.9 grade point average, he is guaranteed to receive the honors scholarship.Treating a condition that is necessary to achieve a result as sufficient to guarantee that result.
- A survey of fifty patrons exiting a high-end boutique in the financial district found that a majority supported higher tariffs on foreign luxury items. Thus, the general public clearly supports these tariffs.Drawing a broad conclusion about an entire population from a biased or unrepresentative sample.
Answer
The argument concerning council voting aligns with inferring causation from temporal sequence; the argument regarding the engineer aligns with attacking personal motives; the argument regarding scholarship qualification aligns with confusing necessary and sufficient conditions; and the argument regarding boutique patrons aligns with generalizing from an unrepresentative sample.
Each pair correctly matches an argument with the precise flaw that undermines its reasoning: confusing temporal sequence with causation, dismissing an argument based on personal motives, treating a necessary condition as sufficient, and drawing a conclusion about a whole population from an unrepresentative sample.
Step-by-Step Solution
Key Concept
Identifying formal and informal reasoning flaws in logical arguments