Rhetorical analysis treats opposition broadly. Both real and conceptual contrasts may be relevant, alongside affirmation/negation, absence/possession, and related oppositional relationships.
RelationIllustration
ContrarietyLife / death
Affirmation/negationKnows / does not know
Contextual contrastFigurative giving of life / death
The point is how a pair of opposed meanings is made relevant to one utterance, not the reduction of all logical relations to a single philosophical category.