This dissertation on The literary and philosophical influences on Ramón del Valle-Inclán’s La lampara maravillosa (LLM) is comprised of two parts. The first part examines the influence of the heterodox philosophies on which LLM is based, focusing particularly on Spiritism, a movement that developed greatly in Spain, but is yet to be widely studied. Basic concepts in Valle-Inclán’s LLM, such as reincarnation or the law of retribution or karma, are found in spiritist circles in Spain, which started proliferating throughout the country from 1868. This dissertation examines a little-known publication within Spanish literary historiography: the Revista de Estudios Psicológicos (REPs) of Barcelona, which informed readers about Spiritism as well as those who researched its phenomena, among whom Manuel Otero Acevedo, a friend of Valle-Inclán who had travelled to Italy in order to study the medium Eusapia Palladino, could be found. Otero Acevedo’s stay in Italy and influence on the development of Valle-Inclán’s heterodox thinking are also studied in this work. Otero Acevedo was a representative for so-called Psychism, a scientific interpretation of spiritist phenomena. The REPs organized the First International Spiritist Congress in Barcelona in 1888, which led to the International Spiritualist Congress of Paris, in 1889, where thriving heterodox trends started to be seen, such as Theosophy and Occultism. The former spread Orientalism and esoteric thought within Spanish Modernism. In parallel with this, French finisecular Occultism, tightly bound to literary Symbolism, also contributed to this spread, and so it is portrayed in LLM, an aesthetic essay based on occultist metaphysics that proposes a purely symbolic style of poetry. In conclusion, LLM is the result of a nearly forty-year-long tradition of publications on Spiritism, Theosophy and Occultism, which disappeared due to the repression that occurred right after the Spanish Civil War. In the second part of this research project, dedicated to the exegesis of every single section of LLM, a new interpretation of this essay is outlined; the characteristics of the brother in pilgrimage, the implied reader of the essay, are described; and some of the illustrations, variations and typographical errors within existing editions are discussed. According to Valle-Inclán, LLM delineated a mystical aesthetic, but it is not about a mystical union with the Catholic God, but rather with a God, the All, close to the model proposed by Emerson’s Transcendentalism or by movements like Occultism and Theosophy. In fact, traditionalist and heterodox influences smoothly coexist in the postulates of LLM. In El Anillo de Giges, the author elucidates his theory of the world, his idea of beauty bound to divinity and the role of the poet-artist, who is able to perceive the invisible. In El Milagro Musical, Valle-Inclán reflects on the linguistic expression of emotions, the limitations within language itself and the need to broaden the meaning of words through musicality. In Exégesis Trina, the author expresses his theory on Trinitarian art, which is the result of applying the theological Trinity to art. In this theory, the Quietismo Estético represents the art of the Spirit, defined by the author as an aesthetic expression of an awareness obtained through remembrance, which is based on an esoteric understanding of the world and human existence. Thus, Valle-Inclán considers the very last act of men, i.e. dying, to be the true expression of the moral conscience of personality. In this regard, the poet must express the spiritual state of men, their eternal responsibility. Finally, in La Piedra del Sabio, it is specifically stated that the aesthetic essay La lámpara maravillosa is an alchemical piece of work, where a transformation and a transmutation take place between the narrator and the implied reader.