A fallacy is a mistake in the logic of one’s thinking or communicating which leads to wrong conclusions. We as those who desire to be clear thinking and accurate about the properties of reality need to be familiar with fallacies as we are presented with them, in order to hone our ability to rightly appraise truth claims.
Definition: The false dilemma informal fallacy occurs when an incomplete number of choices (usually two) are presented as the entire spectrum of options available for a decision, when there are actually others available for consideration.
Examples: “Is United right for your move? Ask yourself: do you want (A) a seamless professional move? Or (B) your possessions set on fire? (A) technology experts to set up your home network? Or (B) raccoons to run amok with your electronics? (A) portable containers to move yourself? Or (B) complete chaos? If you answered A, call United.” (television commercial for United Van Lines, 2011) [from here]
“You must vote either Democrat or Republican.”
“Either you have faith, or you have knowledge.”
“If God is all good, he would want to get rid of evil. If God is all powerful, he would be able to get rid of evil. Since evil exists, God must not.”
Recognizing the fallacy: Often when in a situation that can be characterized as “between a rock and a hard place,” some hidden third option should be sought. But, some dilemmas are true logical dichotomies, in the form A (or) not A, in which by the law of excluded middle, no third option can even in principle be possible, such as, “Either God exists, or he does not exist.”