rationality, which nonetheless is one of the foundations of the Alice books. Symbolic Logic, the handbook to which he devoted the end of his life, would thus appear as an ultimate attempt to save ontology, imperilled by his literary work. The mathematization and formalization of logic that developed in the second half of the nineteenth century tried to extricate this science from natural languages and to free it from their ambiguities. This resulted in a complete re-shaping of logic that broke with the tradition of the ontological import of language. Although he knew of Boole's and Venn's earlier works, Lewis Carroll seems to have tried to integrate some of the contributions of his contemporaries into traditional logic in order to save Aristotle's theses and to protect logic and language from this attack on ontology. His literary work, notably the Alice books and The Hunting of the Snark, can thus be read in the light of his Symbolic Logic, which reveals that what was at stake were questions of sense and of the ontological import of language. Jean-Jacques Lecercle has shown that Nonsense as a "meta-literary" genre aims to disclose the structures generating sense and is a way of structuring Lewis Carroll's work against the chaos that threatens it.' Chaos indeed finds its expression in the mathematician's work on geometry and logic, in the figures of emptiness and infinity. In the Alice books, these two figures are linked to his intuition of emptiness and "non-sense" as the basis of the subject and of language, as well as being linked to jouissance, which threatens the classical rationality on which his work nevertheless relies. The dialogue between logic and literature seems to develop between the two poles of conscious and unconscious knowledge, which the mathematician sensed when he realized that the price of the formalization of logic was ontology, which had to suffer a major blow in order to be saved.