Golden Mean - Golden Section - Delphi - entasis and other optical refinements
A) Golden Mean: Proportion considered aesthetically pleasing; Examples: Fibonacci sequence, golden ratio.
B) Golden Section: Division of a line into two parts in such a way that the ratio of the smaller part to the larger part is the same as the ratio of the larger part to the whole.
C) Delphi: Ancient Greek sanctuary dedicated to Apollo; Examples: Oracle of Delphi, Delphic Games.
D) Entasis and other optical refinements: Architectural techniques to create the illusion of straightness; Examples: Curvature of columns in Greek temples.