"I cannot imagine how this could be true; therefore, it must be false."
Assumption that if an argument for some conclusion is fallacious, the conclusion must also be false.
A claimed authority's support is used as evidence for an argument's conclusion.
Assuming that something which is true of a thing must also be true of some or all of its parts (reverse of the Fallacy of Composition).
Assuming that something true of part of the whole must also be true of the whole.
"I shall never be ashamed of citing a bad author if the line is good." - Seneca
The consequence of the phenomenon is claimed to be its root cause. Example: "Sue is lethargic and has poor hygiene habits, therefore, she is depressed." (In other words, Sue is depressed because she's lethargic and has poor hygiene habits.) Here, the consequences (lethargy, poor hygiene) of the phenomenon (depression) are being claimed as the root …
Assuming that because there is a lack of textual or spoken evidence from an authoritative source, a certain claim is true, or vice versa.
Ever been stuck in an argument, knowing that the other person's logic is faulty, but not knowing exactly why or how?