fallacy

False dilemma

Also called: False dichotomy, Either-or fallacy, Black-and-white thinking

A false dilemma presents two options as the only possibilities when others exist, so that rejecting one seems to force acceptance of the other.

How it works

By shrinking the field to two choices, usually one attractive and one terrible, the speaker makes their preferred option look inevitable. Middle positions, combinations and entirely different options disappear from view.

Examples

"Either we cut taxes or the economy will never grow."

Growth can come from many sources; tax cuts are one option among several.

"You're either with us on this bill or you don't care about children."

Someone can care about children and still think this particular bill is a poor way to help them.

How to spot it

"Either... or..." with nothing in between.
Disagreement with one option is treated as support for the other.
The two options are not actually exhaustive.

How to respond

Name a third option, or a combination of the two.
Ask why these are the only choices.
Say which parts of each option you accept and which you reject.