Self-study
Linguist: Support Only if a sentence can be diagrammed is it grammatical. ███ ███████████ ████████ ██ ██████████ ██ ███████████ ██ ████████ ██ ███ █████████ ███████ ███ ████████ ███ ██ ███████████ ███ ███████ ███ ████████ ████ ██ ██████████ ██ ███████████ ██ ████████ ██ ███ █████████
Summarize Argument
The linguist concludes that speaker X’s sentence will be recognized as grammatical by speakers of its language. As premises, he gives three claims:
(1) If a sentence is grammatical, it is diagrammable.
(2) If a sentence is grammatical, it will be recognized as grammatical by speakers of its language.
(3) Speaker X’s sentence is diagrammable.
Identify and Describe Flaw
The linguist mistakes sufficiency and necessity. He assumes that because speaker X’s sentence is “diagrammable,” it is also “grammatical,” and therefore “recognizable.” But “grammatical” is the sufficient condition for “diagrammable,” not the other way around. Perhaps speaker X’s sentence is “diagrammable” but is not grammatical, and is therefore not “recognizable.”
In other words, he draws a conditional connection between “diagrammable” and “recognizable” when no such connection exists.
8.
The linguist's reasoning is flawed ███████ ██ █████ ██ ████████ ███ ███████████ ████
a
most people are ██████ ██ ███████ █████████ █████████
This wouldn’t damage the argument, so overlooking it can’t be a flaw. Even if most people can't diagram a sentence correctly, it doesn't affect whether the sentence can be diagrammed.
b
some ungrammatical sentences ███ ████████████
This points out the linguist’s key flaw. He draws a conditional connection between “diagrammable” and “recognizable” when no such connection exists. It could be that speaker X’s sentence is diagrammable but is ungrammatical. In that case, the conclusion would fall apart.
c
all sentences recognized ██ ███████████ ███ ██ ██████████
If this were true, it wouldn’t impact the linguist’s argument either way. His argument rests on the mistaken assumption that all sentences that can be diagrammed can also be recognized as grammatical, not the other way around.
d
all grammatical sentences ███ ██ ██████████
The linguist doesn’t fail to consider this. In fact, it’s just restating his first premise: “only if a sentence can be diagrammed is it grammatical.”
e
some ungrammatical sentences ███ ██████████ ██ █████████████
The linguist’s argument only states that all grammatical sentences can be recognized as grammatical. Whether some ungrammatical sentences are recognized as ungrammatical is not relevant.