undistributed middle

noun

1. Logic. a middle term of a syllogism that does not refer to its entire class in the major premise or minor premise, with the result that the syllogism is not valid.

Word History and Origins

Origin of undistributed middle¹

First recorded in 1820–30

Example Sentences

But it would be wrong; our syllogism would have a badly undistributed middle.

From Project Gutenberg

Moreover, not till a man's work is translated can we uncover all the unconscious cases of "undistributed middle."

From Project Gutenberg

You have committed the fallacy of the undistributed middle term, if you care to know the proper name for it.

From Project Gutenberg

For, just as in Fig I., a particular premise anywhere else involves undistributed Middle.

From Project Gutenberg