PrepTest 131, Section 3, Question 23
To predict that a device will be invented,(52 more words not shown)
Which one of the following(11 more words not shown)
- Aconstructing a counterexample(7 more words not shown)
- Bappealing to definitions(9 more words not shown)
- Ccountering a hypothesis(10 more words not shown)
- Dpointing out how(12 more words not shown)
- Eattempting to show(13 more words not shown)
Reading the argument
To predict a device, you need some idea of what it would do. If I predict flying cars, I should at least be able to say they would carry people through the air and change how people travel. So far, I can follow the requirement for a conception of the device.
But the author then defines inventing as developing a detailed conception. On that definition, forming the conception needed for the prediction would already amount to inventing the thing. Since a prediction cannot concern something that has already happened, the author concludes that predicting an invention is impossible.
I'm not convinced that describing a flying car means I've invented one. Nor would saying “a treatment that cures cancer” mean I've solved the problem of creating that treatment. We could question how much detail an invention requires and whether the description involved in a prediction really supplies it.
What we’re looking for
The question asks for the reasoning technique, though. We can describe the author's method without accepting it: use definitions of inventing and predicting to argue that a certain kind of prediction cannot occur.
Working the answers
- A
The argument gives no concrete counterexample to a general prediction about the future. It reasons about what inventing and predicting mean. The flying-car example we considered was a way of questioning that reasoning, not an example the author supplied.
- BCorrect
The definition of inventing makes the required conception count as an invention already accomplished. The restriction on predicting something already done then makes predicting an invention impossible, according to the argument. B captures both the appeal to definitions and the kind of occurrence being ruled out.
- C
This would involve drawing implications from a hypothesis and showing that those implications are false. Here, the author argues that two descriptions cannot fit together under the meanings supplied. The passage doesn't test a hypothesis against a false factual consequence; its reasoning turns on the definitions.
- D
Nothing says that the problem is widely regarded as scientific or that the author is correcting that popular view. The argument may be about concepts, but D adds a contrast with a supposed widespread scientific understanding that the passage never describes.
- E
“Any event” is too broad. The argument concerns predicting inventions because of what it says inventing involves. It doesn't claim that predicting rain, for example, makes the rain already have occurred. E removes the restriction that the argument depends on.
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