De architectura

Vitruvius, a Roman architect and military engineer, wrote *De architectura* (known in English as *On Architecture* or *Ten Books on Architecture*) for his patron, Emperor Caesar Augustus, to serve as a guide for building projects. It is the only architectural treatise to have come down from the ancient world, and since the Renaissance it has been considered the first known work on architectural theory, as well as a key source for the classical architectural canon.

The text gathers information on Greek and Roman buildings and offers prescriptions for planning and designing military camps, cities, and structures both large—such as aqueducts, buildings, baths, and harbours—and small, including machines, measuring devices, and instruments. Because Vitruvius wrote early in the Roman architectural revolution, before cross vaulting, domes, concrete, and other hallmarks of Imperial Roman architecture were fully developed, his ten books provide little detail on those distinctive innovations.

Original copies likely contained a few illustrations—perhaps eight or ten—based on references in the text, but only one may have survived in any medieval manuscript. This lack was addressed in 16th-century printed editions, which included many large plates. Manuscript copies were produced during the Carolingian Renaissance, but they saw little use until the 15th century, when the work gained great interest and influence, first in Italy and then across Europe.

Probably composed between 30 and 20 BC, the treatise draws on the knowledge and views of many Greek and Roman writers on architecture, the arts, natural history, and building technology. Vitruvius frequently cites authorities, praising Greek architects for developing temple building and the Doric, Ionic, and Corinthian orders, and provides key accounts of the origins of building in the primitive hut. He advises on the qualifications of an architect in Book I and on types of architectural drawing. Although often quoted for his famous triad of architectural characteristics—*utilitas*, *firmitas*, and *venustas* (utility, strength, and beauty)—the aesthetic principles that later influenced treatise writers are outlined in Book III. Derived partly from Latin rhetoric through Cicero and Varro, Vitruvian terms for order, arrangement, proportion, and fitness for purpose have guided architects for centuries.

The ten books cover a wide range of subjects Vitruvius saw as touching on architecture, including mathematics, astronomy, meteorology, and medicine. In the Roman view, architecture had to account for everything affecting the physical and intellectual life of humans and their surroundings. For example, in Book II, Vitruvius advises architects working with bricks to understand pre-Socratic theories of matter to predict how materials will behave. Book IX relates Plato’s abstract geometry to the surveyor’s daily work. Astrology is cited for insights into organizing human life, and astronomy is needed for understanding sundials. Vitruvius also references Ctesibius of Alexandria and Archimedes for their inventions, Aristoxenus for music, Agatharchus for theatre, and Varro for architecture.

Vitruvius sought to address the ethos of architecture, declaring that quality depends on the social relevance of the artist’s work, not on form or workmanship alone. The most famous declaration from the work—often quoted as “Well building hath three conditions: firmness, commodity, and delight”—comes from Sir Henry Wotton’s 1624 translation of a passage in Book I, chapter iii, section 2. In modern English, it reads: “The ideal building has three elements; it is sturdy, useful, and beautiful.” Vitruvius also studied human proportions in Book III, and this part of his canons was later adapted in Leonardo da Vinci’s famous drawing *Homo Vitruvianus* (“Vitruvian Man”).

On domestic architecture, Vitruvius gives a mixed message. While he offers admiration for householders who built their own homes without an architect—similar to Aristotle—his ambivalence is clearest in the introduction to Book 6, which focuses exclusively on residential architecture. Instead of writing about the virtues of residences or family life, Vitruvius relates an anecdote about the Greek ethical principle of *xenia*: showing kindness to strangers.

The treatise is also important for its descriptions of machines used for engineering structures—such as hoists, cranes, and pulleys—and war machines like catapults, ballistae, and siege engines. Vitruvius describes the construction of sundials and water clocks, as well as the use of an aeolipile, the first steam engine, as an experimental demonstration.