A false dilemma (also called black-and-white thinking, bifurcation, denying a conjunct, the either-or fallacy, false dichotomy, fallacy of exhaustive hypotheses, the fallacy of false choice, the fallacy of the false alternative, or the fallacy of the excluded middle) is a type of informal fallacy that involves a situation in which only limited alternatives are considered, when in fact there is at least one additional option. The opposite of this fallacy is argument to moderation.
The options may be a position that is between two extremes (such as when there are shades of grey) or may be completely different alternatives. Phrasing that implies two options (dilemma, dichotomy, black-and-white) may be replaced with other number-based nouns, such as a "false trilemma" if something is reduced to only three options, instead of two.
False dilemma can arise intentionally, when fallacy is used in an attempt to force a choice (such as, in some contexts, the assertion that "if you are not with us, you are against us"). This fallacy also can arise simply by accidental omission of additional options rather than by deliberate deception.
Some philosophers and scholars believe that "unless a distinction can be made rigorous and precise it isn't really a distinction." An exception is analytic philosopher John Searle, who called it an incorrect assumption that produces false dichotomies. Searle insists that "it is a condition of the adequacy of a precise theory of an indeterminate phenomenon that it should precisely characterize that phenomenon as indeterminate; and a distinction is no less a distinction for allowing for a family of related, marginal, diverging cases." Similarly, when two options are presented, they often are, although not always, two extreme points on some spectrum of possibilities; this may lend credence to the larger argument by giving the impression that the options are mutually exclusive of each other, even though they need not be. Furthermore, the options in false dichotomies typically are presented as being collectively exhaustive, in which case the fallacy may be overcome, or at least weakened, by considering other possibilities, or perhaps by considering a whole spectrum of possibilities, as in fuzzy logic.
Morton's fork, a choice between two equally unpleasant options, is often a false dilemma. The phrase originates from an argument for taxing English nobles:
- "Either the nobles of this country appear wealthy, in which case they can be taxed for good; or they appear poor, in which case they are living frugally and must have immense savings, which can be taxed for good."
This is a false dilemma and a Catch-22, because it fails to allow for the possibility that some members of the nobility may in fact lack liquid assets, as well as the possibility that those who appear poor, may be poor.
The presentation of a false choice often reflects a deliberate attempt to eliminate several options that may occupy the middle ground on an issue. A common argument against noise pollution laws involves a false choice. It might be argued that in New York City noise should not be regulated, because if it were, the city would drastically change in a negative way. This argument assumes that, for example, a bar must be shut down to prevent disturbing levels of noise emanating from it after midnight. This ignores the fact that the bar could simply lower its noise levels, or install soundproofing structural elements to keep the noise from excessively transmitting onto others' properties.
In psychology, a phenomenon related to the false dilemma is black-and-white thinking. Many people routinely engage in black-and-white thinking, an example of which is someone who categorizes other people as all good or all bad.
- Correlative-based fallacies
- Degrees of truth
- Hobson's choice
- Law of excluded middle
- Loaded question
- Love–hate relationship
- Multi-valued logic
- Nolan Chart
- Pascal's Wager
- Principle of bivalence
- Rogerian argument
- Sorites paradox
- Strange loop
- Thinking outside the box
- Two-party system
- None of the above
- One-party system
- Show election
- Jacques Derrida (1991) Afterword: Toward An Ethic of Discussion, published in the English translation of Limited Inc., pp.123-4, 126
- Searle, John. (1983) The Word Turned Upside Down. The New York Review of Books, Volume 30, Number 16, October 27, 1983.
- Evans, Ivor H. (1989). Brewer's Dictionary of Phrase & Fable, 14th edition, Harper & Row. ISBN 0-06-016200-7.
- AJ Giannini. Use of fiction in therapy. Psychiatric Times. 18(7):56-57,2001.
- The Black-or-White Fallacy entry in The Fallacy Files