False dilemma

The formal fallacy of false dilemma—also known as false choice, false dichotomy, falsified dilemma, fallacy of the excluded middle, black and white thinking, false correlative, either/or fallacy and bifurcation—involves a situation in which two alternative statements are held to be the only options, when in reality there exist one or more other options which have not been considered. The two alternatives presented are often, though not always, the two extreme points on some spectrum. Instead of such extreme simplification and wishful thinking, considering the whole spectrum, as in fuzzy logic, may be more appropriate. A typical false dilemma is the assertion "You are either for us or you are against us." The fallacy of this type of argument is that it tries to eliminate the middle ground.

The false dilemma fallacy refers to misuse of the or operator. For misuse of the and operator, see package-deal fallacy.

A false dilemma may not necessarily be limited to two choices; it may involve three possibilities, in which case it is known as a trifurcation, or more, in which case the dilemma may be more the result of accidental omission than deliberate intent.

Examples

"Mark is late for work. Either his car has broken down, or he has overslept. We telephoned and learned he isn't at home, so his car must have broken down."

This argument is a false dilemma, because there are many other reasons why Mark may have been late for work (he might have decided to quit his job unannounced, he might have been arrested for traffic offences, he might have died, and so on). If it were somehow proven that there were no other possibilities than those presented in the initial dichotomy, then the logic would be sound. But until then, the argument is fallacious. Another example is:

"Nobody shoots anybody in the face unless you're a hitman or a videogamer."

This is an obvious false dilemma, because it ignores both the fact that exclusion is not inherent (i.e. one could be both a hitman and a videogamer, a less-likely scenario) and the fact that there is no logical reason prohibiting non-hitmen non-videogamers from shooting people in the face.

False choice

False dilemmas are also common in politics. They are often hidden in rhetorical questions, and then become akin to the fallacy of many questions, as in:

Will you re-elect the ruling party, or face nuclear holocaust?

Are you with us, or with the forces of racism and oppression?

Are you a Republican or are you a Democrat?

Either you are with us, or you are with the terrorists.

The chooser is forced to decide between absolute commitment or absolute non-commitment. Thus, the possibility of compromise is discounted. Such absolutism is applicable in science and mathematics, in which problems can have one and only one solution, although it is still not necessarily valid (e.g., Do two and two make five or six?). In philosophy, however, there may be fewer absolutes than in other disciplines.

Morton's Fork

Very often a Morton's Fork, a choice between two equally unpleasant options, is 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, because it might be the case that the nobility appear poor and actually do not have much savings to spare.

See also

• Correlative-based fallacies
• Descartes' Error
• Law of the excluded middle, whose misapplication is sometimes the cause of this fallacy
• Pascal's Wager
• You're either with us, or against us