The classical Greek noun that best translates to the English-language words "beauty" or "beautiful" was κάλλος, kallos, and the adjective was καλός, kalos. However, kalos may and is also translated as ″good″ or ″of fine quality″ and thus has a broader meaning than mere physical or material beauty. Similarly, kallos was used differently from the English word beauty in that it first and foremost applied to humans and bears an erotic connotation.
The Koine Greek word for beautiful was ὡραῖος, hōraios, an adjective etymologically coming from the word ὥρα, hōra, meaning "hour". In Koine Greek, beauty was thus associated with "being of one's hour". Thus, a ripe fruit (of its time) was considered beautiful, whereas a young woman trying to appear older or an older woman trying to appear younger would not be considered beautiful. In Attic Greek, hōraios had many meanings, including "youthful" and "ripe old age".
The earliest Western theory of beauty can be found in the works of early Greek philosophers from the pre-Socratic period, such as Pythagoras. The Pythagorean school saw a strong connection between mathematics and beauty. In particular, they noted that objects proportioned according to the golden ratio seemed more attractive. Ancient Greek architecture is based on this view of symmetry and proportion.