He also wrote a rhetoric of Baroque literature, that starts from the texts to redefine the figures of speech of the time, because they did not relate to the classical models. It is a treaty on the concept, which he defines as "an act of the understanding which expresses the correspondence that is found between the objects". That is to say, a concept is every association between ideas or objects. To their classification and dissection Gracián dedicated his "Art of talent, treatise on the witticism" (1642), extended and reviewed in the later "Witticism and art of talent" (1648).