In the judgment of Vitruvius an architect should be a good writer, able to give a lucid explanation of his plans, a skillful draftsman, versed in geometry and optics, expert at figures, acquainted with history, informed in the principles of physics and of ethics, knowing something of music (tones and acoustics), not ignorant of law, or of hygiene, or of the motions, laws, and relations to each other of the heavenly bodies. For, since architecture "is founded upon and adorned with so many different sciences, I am of opinion that those who have not, from their early youth, gradually climbed up to the summit, cannot without presumption, call themselves masters of it."
Vitruvius was far from sharing the view of Archimedes that art which was connected with the satisfaction of daily needs was necessarily ignoble and vulgar. On the contrary, his interest centered in the practical; and he was mainly concerned with scientific theory by reason of its application in the arts. Geometry helped him plan a staircase; a knowledge of tones was necessary in discharging catapults; law dealt with boundary-lines, sewage-disposal, and contracts; hygiene enabled the architect to show a Hippocratic wisdom in the choice of building-sites with due reference to airs and waters. Vitruvius had the Roman practical and regulative genius, not the abstract and speculative genius of Athens.
The second book begins with an account of different philosophical views concerning the origin of matter, and a discussion of the earliest dwellings of man. Its real theme, however, is building-material--brick, sand, lime, stone, concrete, marble, stucco, timber, pozzolano. In reference to the last (volcanic ash combined with lime and rubble to form a cement) Vitruvius writes in a way that indicates a discriminating knowledge of geological formations. Likewise his discussion of the influence of the Apennines on the rainfall, and, consequently, on the timber of the firs on the east and west of the range, shows a grasp of meteorological principles. His real power to generalize is shown in connection with his specialty, in his treatment of the sources of building-material, rather than in his consideration of the origin of matter.