A false dilemma or false dichotomy is an argument "in which two alternative points of view are held to be the only options" when in fact other reasonable options are available.
The false dilemma is often used as a manipulative tool by claiming that the "only other choice" is something which is obviously unreasonable, unpleasant, or unpalatable. The technique is usually used to persuade its audience of a viewpoint that is some distance from a reasonable, "middle ground" solution; the arguer generally wants the audience to dismiss the possibility of a "middle ground" which they might otherwise agree with.
- The phrase "You're either with us, or you're against us.", often used by George W. Bush and his supporters
- "You're either part of the solution, or you're part of the problem."
One of the most popular philosophical conundrums, the Epimenides paradox, can be resolved by realizing that it is a false dilemma. Epimenides, a Cretan, says "All Cretans are liars." Is he telling the truth?
The paradox is usually explained along these lines:
- According to his own testimony, he is a liar – which, if true, must mean that whatever he says is a lie, and therefore his statement about Cretans is a lie, and Cretans are not liars – which would mean that Epimenides, a Cretan, was not a liar – which means he must be lying about Cretans being all liars (because he's one of them and he's telling the truth), which makes him a liar, in which case he's right about Cretans...
The problem is that this is being framed as having only two possible conclusions – either
- all Cretans are liars, in which case Epimenides's claim about Cretans is also a lie, so Cretans must not be liars after all (paradox!)
- all Cretans are not liars, in which case Epimenides is telling the truth, which leads back to the conclusion that all Cretans must be liars because Epimenides says so (paradox!)
The resolution is that there are other possibilities:
- Epimenides is lying – only some Cretans are liars, and he is one of them.
- Epimenides is only exaggerating, not lying; only some Cretans are liars, and he isn't one of them.
- People who are "liars" sometimes tell the truth, and Epimenides (although generally a liar) is doing so in this case.
Note that subtle changes in the definition of "liar" (does "exaggeration" qualify as "lying"? is someone who lies a lot but sometimes tells the truth still a "liar"?) lead to rather different conclusions. This is why it is important to remember that the map is not the territory – i.e. the words we use to describe a situation may misrepresent it in subtle ways that can dramatically affect our conclusions.
- Interpretive framing often presents situations using a false dilemma.
- In cognitive therapy [W], the false dilemma is called "all-or-nothing thinking" or "black-and-white thinking" and is a form of cognitive distortion [W], i.e. a bad habit-of-thought to be overcome due to its ability to prevent sane, moderate choices from being made.