Pattern
The fallacy of the undistributed middle takes the following form:
- All Zs are Bs
- Y is a B
- Therefore, Y is a Z
This can be graphically represented as follows:
where the premises are in the green box and the conclusion is indicated above them.
Here, B is the middle term, and it is not distributed in the major premise, "all Zs are Bs".
It may or may not be the case that "all Zs are Bs," but this is irrelevant to the conclusion. What is relevant to the conclusion is whether it is true that "all Bs are Zs," which is ignored in the argument. The fallacy is similar to affirming the consequent and denying the antecedent. However, the fallacy may be resolved if the terms are exchanged in either the conclusion or in the first co-premise. Indeed, from the perspective of first-order logic, all cases of the fallacy of the undistributed middle are, in fact, examples of affirming the consequent or denying the antecedent, depending on the structure of the fallacious argument.
Read more about this topic: Fallacy Of The Undistributed Middle
Famous quotes containing the word pattern:
“It was her stern necessity: all things
Are of one pattern made; bird, beast, and flower,
Deceive us, seeming to be many things,
And are but one. Beheld far off, they differ
As God and devil; bring them to the mind,
They dull its edge with their monotony.”
—Ralph Waldo Emerson (1803–1882)
“It is just possible that the tensions in a novel of murder are the simplest and yet most complete pattern of the tensions on which we live in this generation.”
—Raymond Chandler (1888–1959)
“Why it was that upon this beautiful feminine tissue, sensitive as gossamer, and practically blank as snow as yet, there should have been traced such a coarse pattern as it was doomed to receive; why so often the coarse appropriates the finer thus, the wrong man the woman, the wrong women the man, many years of analytical philosophy have failed to explain to our sense of order.”
—Thomas Hardy (1840–1928)