A correlative conjunction is a relationship between two statements where one must be false and the other true. In formal logic this is known as the exclusive or relationship; traditionally, terms between which this relationship exists have been called contradictories. Examples of correlatives are:

A: Object one is larger than object two.

B: Object one is smaller or the same size as object two.

A: Fido is a dog.

B: Fido is not a dog.

Fallacies based on correlatives include:

• The false dilemma or false correlative. Here something which is not a correlative is treated as a correlative, excluding some other possibility.
• The fallacy of denying the correlative, where an attempt is made to introduce another option into a true correlative.
• The fallacy of suppressed correlative, where the definitions of a correlative are changed so that one of the options includes the other, making one option impossible.