This may be the most well-known fallacy of presumption:

The most well-known fallacy of presumption is "begging the question".

Begging the question is the fallacy of using the conclusion of the argument as one of the grounds offered in the succeeding support. While this happens in an implicit or explicit fashion, an explicit version would appear like this:

· All chicken are birds.

· All birds have feathers.

· Since animal with feathers bear eggs, chicken bear eggs.

· But all animals with feathers that bear eggs are birds.

· Therefore, all chicken are birds.

Unlike other fallacies, begging the question involves an argument or set of arguments that is properly valid: if its grounds (including the first) are true, then the conclusion must be true.