Card 16 of 24 · Ambiguity
Fallacia compositionis / divisionis
Confusing the tree with the forest.
What’s true of one part isn’t automatically true of the whole, and vice versa.
Example
“That player is excellent, so the entire team must be excellent.”
Or: “The team struggled, so every player must have played poorly.”
Two of Aristotle’s fallacies “dependent on language” in Sophistical Refutations: attributing properties of parts to the whole (composition) or of the whole to the parts (division).
Diagnosis: Some properties transfer between parts and wholes (mass, color sometimes) and many do not (being excellent, being a team). The inference needs a premise showing F is the transferable kind.
“Every event in the universe has a cause, so the universe has a cause.” Bertrand Russell pressed this composition objection against Copleston; defenders must show why contingency transfers to the whole.
“The church is holy, so every church member is holy.” Ecclesiology distinguishes the holiness of the body from the sanctification of its members.
“The Bible is inspired, so every verse can be applied as a timeless command.” Inspiration of the whole doesn’t erase genre and context in each part.
Trail recovery
Ask whether the property is the kind that transfers. In papers, state explicitly why your part-whole move is legitimate.
Try saying: “Does that quality carry over from the parts to the whole here, or is it the kind that doesn’t?”
Keep questioning. Keep exploring.