Appeal to consequences, also known as argumentum ad consequentiam (Latin for “argument to the consequences”), is an argument that concludes a hypothesis (typically a belief) to be either true or false based on whether the premise leads to desirable or undesirable consequences. This is based on an appeal to emotion and is a type of informal fallacy, since the desirability of a consequence does not make it true. Moreover, in categorizing consequences as either desirable or undesirable, such arguments inherently contain subjective points of view.
In logic, appeal to consequences refers only to arguments that assert a conclusion’s truth value (true or false) without regard to the formal preservation of the truth from the premises; appeal to consequences does not refer to arguments that address a premise’s consequential desirability (good or bad, or right or wrong) instead of its truth value. Therefore, an argument based on appeal to consequences is valid in long-term decision making (which discusses possibilities that do not exist yet in the present) and abstract ethics, and in fact such arguments are the cornerstones of many moral theories, particularly related to consequentialism.