Traditionally disregarded as deviant and even ungrammatical, conflictual complex meanings have the epistemological privilege to shed light on both grammar and figurative language. In the field of grammar, the observation of conceptual conflicts allows to dissociate the formal and conceptual factors of the ideation of complex meanings, and thus shows the twofold nature of grammar and linguistic coding. In the field of figurative language, the study of conflictual instances readmits living metaphors to the mainstream of linguistic description, and it also highlights some relevant differences that are discarded by the observation of conventional instances - namely, the difference between oxymoron, metonymy and metaphor on the one hand, and between conventional and living figures on the other.