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 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.
Are you nice or are you kind? You can't be both!
"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 …
The saddest aspect of life right now is that science gathers knowledge faster than society gathers wisdom. - Isaac Asimov
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?
Nobody made a greater mistake than he who did nothing because he could do only a little. - Edmund Burke
(Five of them...).