An archaeologist argues: 'Pottery fragments from the ancient Zanthian culture found in coastal excavations are consistently much harder than those found at inland Zanthian sites. This proves that centuries of exposure to salty coastal air chemically strengthened the clay.'
To protect this causal argument from criticism, the archaeologist must assume several 'defender' statements that rule out alternate explanations. Match each alternate explanatory objection below to the specific defender assumption that logically neutralizes it.
- The coastal Zanthians may have fired their pottery at much higher temperatures than inland Zanthians did.There was no significant difference in the heat levels of the kilns used by the two regional groups.
- The raw clay deposits available in the coastal region might have naturally contained more hardening silicates than inland deposits.The unworked geological materials accessible to coastal potters were not inherently stronger than those used inland.
- The harsh coastal climate may have completely destroyed all but the most durable pottery, whereas inland conditions preserved weaker pieces.Environmental erosion did not act as a disproportionate filter for preserving only the strongest artifacts in the coastal areas.
- Coastal Zanthians might have deliberately designed their pottery to be substantially thicker to withstand rough ocean travel.The intended structural dimensions and thickness of the pottery produced in the two regions were essentially comparable.
Answer
The correct matches pair each specific alternate causal explanation with the negative assumption that explicitly rules it out. The firing temperature objection matches the assumption about kiln heat; the raw clay objection matches the assumption about unworked geological materials; the climate destruction objection matches the assumption about environmental filtering; and the deliberate thickness objection matches the assumption about structural dimensions.
Each correct pair successfully matches a specific threat to the argument's causal conclusion with the negative assumption that neutralizes that precise threat. In Logical Reasoning, when an author argues that A causes B based on an observed difference, they necessarily assume that no other factor (C, D, or E) caused that difference. Mapping the specific alternate explanation to its corresponding negative assumption demonstrates mastery of how 'defender' assumptions operate.
Step-by-Step Solution
Key Concept
Defender Assumptions in Causal Reasoning (Ruling Out Alternate Explanations)