Firmness, commodity, and delight

Firmness, commodity, and delight (Latin: firmitas, utilitas et venustas) are the three aspects of good architecture declared by the Roman architect Vitruvius in his book "De architectura" ("On architecture", 1st century BC) and also known as Vitruvian virtues, Vitruvian Triad. The literal meaning of the Latin phrase is closer to "durability, convenience, and beauty", but the more familiar version is derived from Henry Wotton's liberal translation of Vitruvius, "The Elements of Architecture" (1624): "Well Building hath three Conditions; Commodity, Firmness, and Delight". The theory of architecture has always been concerned with this interrelated triad of structural integrity, proper use of space, and attractiveness. However, the relative importance of each component varied in time, and new elements had been introduced into the mix from time to time (cf. John Ruskin's "The Seven Lamps of Architecture" that include "sacrifice" and "obedience").