The seminal attempt by Ramon Llull to construct a diagrammatic model of the movements of the human psyche was expounded in his Ars Magna of 1305, and in didactic form in his Ars Breve of 1308. Peirce also used geometric diagrams in his proposals for binary connectives in the truth tables of symbolic logic. Even Copernicus, Galileo, Kepler, Tycho Brahe, and other great precursors of the contemporary view of the cosmos were obligated to pay tribute to the naive geocentric cosmovision that was imbued with astrology. In the modern era, from the macrocosmic Keplerian solar system to the microcosmic atom of Rutherford, there are many examples of the heuristic richness of modeling in the resolution of problems. The chapter examine the use and understanding of geometrically ordered diagrams by a number of important traditions and thinkers throughout history, focusing on the set of relations in these diagrams that establish a structure that is determinant in the explanation of phenomena.