Historians recently discovered that medieval European towns with large centralized grain silos experienced significantly fewer winter disease outbreaks than towns with decentralized, individual storage. The historians concluded that the centralized storage system directly caused this improvement in public health.
Match each alternative explanation (causal objection) for this correlation with the specific defender assumption required to rule it out.
- Wealthier towns, which could afford better overall sanitation, were the only communities that could afford to build centralized silos.The towns that implemented centralized silos did not simultaneously benefit from superior hygiene systems.
- Communities that already enjoyed superior baseline health were the only ones capable of the intense coordinated labor needed to construct massive silos.The towns' pre-existing robust health was not the primary enabler for constructing the storage facilities.
- Towns with centralized silos happened to be located in colder, drier geographic regions where pathogens naturally struggle to survive.The geographical weather patterns in regions with centralized storage were not inherently less hospitable to pathogens.
- During the period analyzed, the towns with centralized silos were subject to a strict trade embargo that prevented the arrival of foreign merchants.Towns with centralized silos were not abnormally isolated from external sources of infection during the evaluated time frame.
Answer
The correct pairings map each specific causal objection to the assumption that explicitly negates that possibility. The third-variable confounder (wealth and sanitation) is neutralized by assuming no superior hygiene systems existed. The reverse causality objection (pre-existing health causing the silos) is neutralized by assuming robust health was not the enabler. Geographic climate advantages are ruled out by assuming weather patterns were not inherently less hospitable to pathogens. Finally, trade embargoes (an independent concurrent factor) are ruled out by assuming the towns were not abnormally isolated.
In Logical Reasoning, when an author concludes that A causes B based purely on a correlation, they must implicitly assume that nothing else caused B (no alternate cause), B didn't cause A (no reverse causality), and no third variable caused both. Each correct matched pair actively defends the author's causal claim by systematically neutralizing one of these specific logical vulnerabilities.
Step-by-Step Solution
Key Concept
Ruling out alternate explanations in causal arguments (Defender Assumptions)