The lanes and streets of the city being set out, the choice of sites for the convenience and use of the state remains to be decided on; for sacred edifices, for the forum, and for other public buildings.

The temple of Ceres should be in a solitary spot out of the city, to which the public are not necessarily led but for the purpose of sacrificing to her.

In setting out the walls of a city the choice of a healthy situation is of the first importance: it should be on high ground, neither subject to fogs nor rains; its aspects should be neither violently hot nor intensely cold, but temperate in both respects.

Nothing requires the architect's care more than the due proportions of buildings.

Beauty is produced by the pleasing appearance and good taste of the whole, and by the dimensions of all the parts being duly proportioned to each other.

Music assists him in the use of harmonic and mathematical proportion.