The Tree of Science, written in Rome between 1295 and 1296, was a version of the Art in the form of an encyclopedia, designed for a non-university audience. Its difference from the medieval compendia containing all knowledge, such as those written by Bartholomaeus Anglicus or Vincent of Beauvais in the 13th century, lies in the fact that Llull made no use of systematic catalogues of data (lists of constellations, of aquatic animals or rhetorical figures, for example), but rather described the framework of general principles which give an account of the multiplicity of the real. His encyclopedia enables one to ‘deduce’ the specific contents of knowledge thanks to the fact that the Art is a single method for all the sciences. In this sense, the Arbre de ciència is a ‘new’ encyclopedia, structured according to a special arboreal symbolism.
The work is divided into sixteen trees. The two final trees have a complementary function: they are the Exemplary Tree and the Tree of Questions. The Exemplary Tree provides narratives, proverbs, or analogies related to the contents of the initial Trees, while the Tree of Questions, which practically doubles the length of the work, recasts all the material in the form of questions, some of which have highly illuminating specific solutions, while others refer to the corresponding place within the previous part.
If the Exemplary Tree and the Tree of Questions have a primarily didactic function, the first fourteen Trees provide a view of reality as a whole consisting of mutually complementary parts, starting with inert beings and ending with God. The point of inflection is the Heavenly Tree, in which we are given an explanation of how the divine principles, namely the Dignities, cause their influence to descend from above, upon the things of the sublunary world, endowing them with life. Thus the Elemental Tree describes the nature of matter (which, in the 13th century, meant its origins in the relations between fire, air, water and earth); the Vegetative Tree analyses the vital functions of feeding and of reproduction; the Tree of the Senses presents the senses of animals and men; the Imaginative Tree investigates the capacity to produce representations from sense data; the Human Tree displays the higher faculties of the rational soul; the Moral Tree is a treatise in two parts upon the virtues and the vices; the Imperial Tree studies the social estates, law and forms of government; the Apostolic Tree analyses the structure of the Church and Canon Law. The Heavenly Tree explains what the spheres, the zodiac, and the planets are from the viewpoint of a geocentric cosmos, presided over by the infinite Divinity. The five remaining Trees deal with purely spiritual beings: these are the Angelic Tree; the Eviternal Tree, which speaks of paradise and hell; the Maternal Tree, concerning the Virgin Mary; the Tree of Jesus Christ, regarding the incarnated Son of God; and the Divine Tree, which deals with theology.
Each of the sixteen Trees has an homologous internal structure, with the result that Llull’s presentation of all the branches of knowledge deploys itself harmoniously, revealing the inter-relations and the links between the different levels of reality: thus all the trees begin with a description of the general principles of each field of knowledge, principles which are always the same; that is to say, they are the principles of the Art. The symbolic structure of this homology has seven parts: roots, trunk, boughs, branches, leaves, flowers and fruit. Here Llull’s creative development is based upon a scholastic precept from the Aristotelian tradition.
See: Arbor Scientiae: der Baum des Wissens von Ramon Lull. Akten des Internationalen Kongresses aus Anlass des 40-jährigen Jubiläums des Raimundus-Lullus-Instituts der Universität Freiburg i. Br., Fernando Domínguez Reboiras, Pere Villalba Varneda, and Peter Walter (eds.), “Instrumenta Patristica et Mediaevalia. Subsidia Lulliana” 1 (Turnholt: Brepols, 2002).