The architectural treatises owned by Ximenez were common throughout collections in the early seventeenth century. They focus entirely on Italian architects, ranging from posthumous illustrated editions of Leon Battista Alberti's De architectura (1565) to Sebastiano Serlio's Tutte le opere d'architettura e prospetiva (1600) and Andrea Palladio's I quattro libri dell'architettura (1601). Printed architectural treatises reached their apogee at the end of the sixteenth century, and by Ximenez's era learned gentlemen were expected to understand the principles of building design. On their most basic level these works provided models of classically inspired structures according to the established orders: Doric, Ionic, Corinthian, Tuscan, and Composite. Following Vitruvius' De architectura libri decem, the major classical architectural source throughout the early modern period, these orders came with specific proportions and forms to be followed. While some early modern treatises provided models of classical ruins, such as Vignola's Regole delle cinque ordine d'architettura (1596), which Ximenez also owned, others like Serlio's presented imagined interpretations. As is apparent from Ximenez's collection, commentaries on the original ten books of architecture by Vitruvius also remained quite popular. Ximenez owned commentaries by Daniele Barbaro (1567), the famous patron of Palladio, and Gulielmus Philander (1545), the only non-Italian author present among the architectural works.
More than providing practical knowledge of construction, for a reader like Ximenez these treatises acted as a kind of moral philosophy. The appreciation of design through learned architectural intelligence could be seen as an exercise of moral judgment or giudizio. These texts imported rhetorical concepts from Horace, Cicero, and Quintilian such as imitation and licentia, imploring the reader to separate good design from bad. As with most classically derived pursuits, architects such as Palladio stressed the imitation of nature, a notion taken directly from Vitruvius. Architects were advised to make all ornament appear functional, rather than merely decorative, and to look to plant life as well as the human body when possible. The exterior of a building should reflect its interior function; for example, the house of a military general should appropriately use a colossal Doric order to project strength. By the early seventeenth century these architectural treatises broached natural philosophy, incorporating 'species theory' from Horace's discussion of types of poetry. Forms were perceived to share similar characteristics, and ornamentation thus became a kind of taxonomy. And while popular treatises like Serlio's were criticized for promoting too much license, books like Vignola's were praised as the model of imitation, adhering to the rules of classical form and by extension directly to nature.
Payne, Alina. The Architectural Treatise in the Italian Renaissance: Architectural Invention, Ornament, and Literary Culture. Cambridge: Cambridge University Press, 1999.
Onians, John. Bearers of Meaning: The Classical Orders in Antiquity, the Middle Ages and the Renaissance. Princeton: Princeton University Press, 1988.