Fallacy?

False dilemma

Only two options are offered when others exist.

Also called: False dichotomy · Either-or

The test

Is there a third possibility the argument leaves out?

Debates about origins are often framed as a contest between two camps, and the framing does a lot of work. It is easy to win an argument by refuting the weakest version of the only alternative allowed.

There is also a version that both camps sometimes share: “if evolution is true, Christianity is false.” Many Christians who accept evolution would deny it, and many critics of evolution do not rest their faith on the outcome. Whatever one concludes, the dilemma itself has to be argued, not assumed.

Seen on both sides

In mainstream arguments
It would be a false dilemma to argue: either unguided evolution, or a designer who made every species exactly as it is today, when most design and creation views expect change within created kinds.
In critical arguments
It would be a false dilemma to argue that either every part of evolutionary theory is true or none of it is, and so to reject well-tested observations of adaptation along with the extrapolation.
Not a fallacy when

The two options really are exhaustive, or the others have been considered and set aside for stated reasons.

Diagnosed on this site

Not yet diagnosed in any pillar or claim card.

Further reading

  1. Copi IM, Cohen C, McMahon K. Introduction to Logic. Pearson, 14th ed. (2011).