Argument in the alternative

Originating in the legal profession, argument in the alternative is a strategy in which a lawyer advances several competing (and possibly mutually exclusive) arguments in order to pre-empt objections by his adversary, with the goal of showing that regardless of interpretation there is no reasonable conclusion other than the advocate's. The notion is closely related to alternative pleading, and the two terms are sometimes used interchangeably.

Source: Wikipedia — Argument in the alternative (CC BY-SA 4.0)