presuppositional

Presuppositional is an adjective relating to presupposition, the idea that certain assumptions are taken for granted within language, argument, or reasoning. In linguistics and semantics, a presupposition is a background belief that must be true for a statement to make sense or for the communication to proceed. Presuppositional expressions are those that carry such implied commitments; examples include adverbs and verbs like again, still, even, stop, or manage to. For instance, the sentence "John stopped smoking" presupposes that John used to smoke, and that the act of stopping is noteworthy. The sentence "The project is still ongoing" presupposes that the project was ongoing in the past. Presuppositions are distinguished from entailments, which are direct logical consequences of a sentence.

In philosophy of language and apologetics, presuppositional reasoning appears in analysis of how statements carry implied commitments and how arguments depend on assumed worldviews. In theology and Christian apologetics, presuppositionalism (or presuppositional apologetics) is a school of argument that maintains that belief in God is a precondition for rational thought and meaningful discourse. Proponents argue that non-Christian worldviews cannot account for the intelligibility of experience, logic, or moral values without presupposing Christian theism. Critics contend that this approach can involve circular reasoning and fails to engage with other worldviews on their own terms.

The term presuppositional can thus appear in linguistic analysis as well as in theological and philosophical debate, among other fields, whenever an argument or utterance relies on assumed background commitments.