Lesson: Challenging Critical/Logical Reasoning - 23t01

Additional Question Types: Correlation/Causation, continued

If too much pressure is exerted on the bottom shelf of a bookcase, the entire bookcase will collapse. Sherry's bookcase has collapsed. Therefore, too much pressure must have been exerted on its bottom shelf. Which one of the following criticisms best describes a weakness in the argument above? It supports its conclusion with irrelevant evidence. It contains a shift in the meaning of the word "collapse" from "partial collapse" to "full collapse." It concludes that an outcome has been caused by a particular factor that may be only one possible cause of the outcome in question. It overlooks the possibility that some bookshelves have only one shelf. It draws an overly broad conclusion from contradictory evidence.

The evidence tells us that exerting too much pressure on the bottom shelf of a bookcase is sufficient to make the bookcase collapse. But that doesn't mean it's the only thing that would cause a bookcase to collapse. Lots of things could — an earthquake perhaps. So the fact that the bookcase has collapsed does not mean that we can conclude someone must have exerted too much pressure on the shelf. As Choice (C) says, that's one possible cause of the outcome in question.

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