In relation to the specific question of the metaphor, a comparison between two cognitive theories - the conceptual metaphor theory (Lakoff and Johnson, 1986) and the conceptual integration theory (Fauconnier and Turner, 1998) - is leading us to note their similarities but also a number of existing differences. These approaches share the idea that a metaphor is based on the initial severance of two entities (conceptual domains or mental spaces), which is to be resolved in a set of conceptual mappings. However, the conceptual integration puts in place a different formal structure, which outlines the dynamic aspect of the problem. As a result, its explanatory capacity reaches the innovating metaphors and the extended metaphors contrary to the conceptual metaphor theory, which is often confined to the most generic conventional metaphor. This advantage of conceptual integration is illustrated with an example from Doderer's novel. Such an example suggests the importance of the optimality principles for the constitution of the integration network and, in particular, of the blending space. (LLBA 2003, vol. 37, n. 2)