Final answer:
The Greek definition of "symmetry" mentioned by Vitruvius is best encapsulated as a balance between elements, which is a harmonious proportional relationship within a design, rather than exact replication or asymmetry.
Step-by-step explanation:
The Greek definition of "symmetry," as transmitted by Vitruvius, is best summarized by the phrase balance between elements. This conception of symmetry involves the use of mathematical ratios and thoughtful design to create a sense of harmony and proportion in art and architecture. Perfect symmetry is not always required; rather, a balanced and harmonious composition can be achieved through proportional relationships, as exemplified by the Greek sculptor Polykleitos in Doryphoros and the architectural design of the Parthenon. The Greeks believed that such symmetrical and proportional design was inherently pleasing to the eye and created a sense of balance, stability, and beauty. Additionally, in art, symmetrical balance entails the mirroring of compositional elements across a central axis, creating an organized and formal design. This concept is also applied to Greek temples, which often feature strict bilateral symmetry to convey a sense of strength and order.