Greco-Roman tradition
The classical Greek noun that best translates to the English-language words "beauty" or "beautiful" was κάλλος, kallos, and the adjective was καλός, kalos. This 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 bore 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". Another classical term in use to describe beauty was pulchrum (Latin).
Beauty for ancient thinkers existed both in form, which is the material world as it is, and as embodied in the spirit, which is the world of mental formations. Greek mythology mentions Helen of Troy as the most beautiful woman. Ancient Greek architecture is based on this view of symmetry and proportion.
In one fragment of Heraclitus's writings (Fragment 106) he mentions beauty, this reads: "To God all things are beautiful, good, right..." The earliest Western theory of beauty can be found in the works of early Greek philosophers from the pre-Socratic period, such as Pythagoras, who conceived of beauty as useful for a moral education of the soul. He wrote of how people experience pleasure when aware of a certain type of formal situation present in reality, perceivable by sight or through the ear and discovered the underlying mathematical ratios in the harmonic scales in music. The Pythagoreans conceived of the presence of beauty in universal terms, which is, as existing in a cosmological state, they observed beauty in the heavens. They saw a strong connection between mathematics and beauty. In particular, they noted that objects proportioned according to the golden ratio seemed more attractive.
The classical concept of beauty is one that exhibits perfect proportion (Wolfflin). In this context, the concept belonged often within the discipline of mathematics. An idea of spiritual beauty emerged during the classical period, beauty was something embodying divine goodness, while the demonstration of behaviour which might be classified as beautiful, from an inner state of morality which is aligned to the good.
The writing of Xenophon shows a conversation between Socrates and Aristippus. Socrates discerned differences in the conception of the beautiful, for example, in inanimate objects, the effectiveness of execution of design was a deciding factor on the perception of beauty in something. By the account of Xenophon, Socrates found beauty congruent with that to which was defined as the morally good, in short, he thought beauty coincident with the good.
Beauty is a subject of Plato in his work Symposium. In the work, the high priestess Diotima describes how beauty moves out from a core singular appreciation of the body to outer appreciations via loved ones, to the world in its state of culture and society (Wright). In other words, Diotoma gives to Socrates an explanation of how love should begin with erotic attachment, and end with the transcending of the physical to an appreciation of beauty as a thing in itself. The ascent of love begins with one's own body, then secondarily, in appreciating beauty in another's body, thirdly beauty in the soul, which cognates to beauty in the mind in the modern sense, fourthly beauty in institutions, laws and activities, fifthly beauty in knowledge, the sciences, and finally to lastly love beauty itself, which translates to the original Greek language term as auto to kalon. In the final state, auto to kalon and truth are united as one. There is the sense in the text, concerning love and beauty they both co-exist but are still independent or, in other words, mutually exclusive, since love does not have beauty since it seeks beauty. The work toward the end provides a description of beauty in a negative sense.
Plato also discusses beauty in his work Phaedrus, and identifies Alcibiades as beautiful in Parmenides. He considered beauty to be the Idea (Form) above all other Ideas. Platonic thought synthesized beauty with the divine. Scruton (cited: Konstan) states Plato states of the idea of beauty, of it (the idea), being something inviting desirousness (cf. seducing), and, promotes an intellectual renunciation (cf. denouncing) of desire. For Alexander Nehamas, it is only the locating of desire to which the sense of beauty exists, in the considerations of Plato.
Aristotle defines beauty in Metaphysics as having order, symmetry and definiteness which the mathematical sciences exhibit to a special degree. He saw a relationship between the beautiful (to kalon) and virtue, arguing that "Virtue aims at the beautiful."
In De Natura Deorum, Cicero wrote: "the splendour and beauty of creation", in respect to this, and all the facets of reality resulting from creation, he postulated these to be a reason to see the existence of a God as creator.