Argument by contradiction

About

Argument by contradiction is any form of argument in which the arguer simply re-asserts that their position is true. It is often accompanied by some form of prop to make it seem more substantial, in which case it is a form of rhetorical deception.

Example:

• A: X is true.
• B: No it isn't; we agreed that Y is true, and X can't be true if Y is true.
• A: Actually, studies show that X is not true even when Y is true.

In this case, A is combining a reassertion of their original position with an argument from authority ("studies show") to distract B's attention from the fact that A is basically saying "Yes it is". Unless A presents the data from those studies, this is an argument based on the presumed authority of a study whose validity cannot be examined.

As Monty Python once observed:

An argument is a connected series of statements to establish a definite proposition. ... It isn't just saying "no it isn't"!