The Occult in Rabelais concerns itself with all references, explicit or implied, to the systems of contemporary occultism in Rabelais’s work. Although a division may be made between those allusions which seem merely to reflect humanist preoccupation with the occult and those which are functional in terms of the proposed allegory, it is argued that all occult references, by supposing the existence of a cosmic dualist (Above and Below), and by supposing the possibility of mutual interaction, support the theme of human perfectibility called the Itinerarium Mentis in Deum. Early references to the occult may therefore be of importance in Pantagruel and Gargantua, not only those from Le Tiers Livre onward, where the theme of perfectibility of will (treated by Rabelais, it is proposed, under the guise of the marriage question) has had time to evolve in the imagination of the author. The thesis covers all occultism which exists in Rabelais under the broad headings: 1 Alchemy, Tarot and the Mysteries 2 Divination 3 Numerology Renaissance and classical sources are listed, the nature and limitations (if any) of the occult systems are treated, examples of their use by Rabelais are noted, and their allegorical implications are discussed. The study suggests the following major conclusions: 1 Alchemy, other similar traditions, divination and numerology may be considered as supplementary aspects of Rabelaisian allegory. 2 An important allegory of the T.L., Q.L. and C.L. involves the Itinerarium mentis in Deum, of which Panurge is the central character. 3 Spiritual alchemy, tarot and the Mysteries provide an occult background to the idea of Itinerarium since they are concerned with human perfectibility. 4 Chapters 33 - 47 of Le Cinquiesme Livre, while full of occult allusions, are thematically necessary to the completion of Rabelais’s work in terms of the allegory proposed. Other conclusions are reached: 1 The weight and role of each occult tradition may change from one book to another. 2 The stages of alchemy called separatio, qeneratio and coniunctio relate to the principles of death, rebirth and marriage respectively, and these principles of the Itinerarium may be found in Rabelais’s work. 3 The progress of Panurge may be related to the progress towards fulfilment of the materia prima of alchemy. 4 Pantagruel and Gargantua come to represent the Salt of alchemy. 5 The stock figures of the tarot coincided with the characters and actions of Rabelais’s work. 6 There are strong links between the Temple of Rabelais and the classical temples of Apollo, and between Rabelaisian and Apolline ritual and mysticism. 7 Divination in Rabelais supports the Itinerarium in that it similarly supposes recourse to a final truth existing in immutability. Panurge may reject contrary divinatory projections, as divination has never had power over the will. This does not mean Panurge is right to do so. 8 The double nature of number (mathematical and ideal) points upward from the material to the divine, and therefore supports the Itinerarium. 9 The true efficacy of the Dive Bouteille as oracle rests in the fact that it is also a Christian mystery. 10 The Temple represents an ideal human body, of which the main temple is the trunk and the circular chapel the head. Panurge is born again (like Pantagruel, from the ear). Panurge can only enter this body by passing via Lanternois.