In Kabye society, the commonest sacrificial rites include a device that may prompt celebrants to question their own ritual practice. As in other West African societies, the acceptance or refusal of an offering by a divinity is read in the death throes of the first chicken to be sacrificed. If the fowl does not die in the expected position, the ceremony is interrupted. Celebrants scrutinize the execution of the rite to identify the mistake that led to the sacrifice's refusal, and they submit their hypothesis to the divinity. However, the resumption of the rite is not conditioned by the correction of the mistake. It is often sufficient that officiants recognize and reassert the rule that they should have followed. The case of a bull sacrifice demonstrates how the celebrants' selfcritical practice may promote a ritual effectiveness in connection with the dialogical and pragmatic nature of the rite. © Berghahn Books.