aesthetics 
From the 1911 Britanica Encyclopedia:

Greek Speculations
Ancient Greece supolies us with 
the first important contributions to aesthetic theory, 
though these are scarcely, in quality or in quantity, what 
one might nave expected from a people which had so high an 
appreciation of beauty and so strong a bent for philosophic 
speculation.  The first Greek thinker of whose views on the 
subject we really know something is Socrates.  We learn from 
Xenophon's account of him that he regarded the beautiful as 
coincident with the good, and both of them are resolvable 
into the useful.  Every beautiful object is so called because 
it serves came rational end, whether the security or the 
gratification of man.  Socrates appears to have attached 
little importance to the immediate gratification which a 
beauriful object affords to perception and contemplation, 
but to have emphasized rather its power of furthering the 
more necessary ends of life.  The really valuable point in 
his doctrine is the relativity of beauty.  Unlike Plato, 
he recognized no self-beauty (auto to kalon) existing 
absolutely and out of all relation to a percipient mind. 

Plato

Of the views of Plato on the subject, it is hardly less difficult 
to gain a clear conception from the Dialogues, than it is in 
the case of ethical good.  In some of these, various definitions 
of the beautiful are rejected as inadequate by the Platonic 
Socrates.  At the same time we may conclude that Plato's mind 
leaned decidedly to the conception of an absolute beauty, 
which took its place in his scheme of ideas or self-exisiing 
forms.  This true beauty is nothing discoverable as an 
attribute in another thing, for these nre only beautiful things, 
not the beautiful itself.  Love (Eros) produces aspiration 
towards this pure idea.  Elsewhere the soul's intuition of the 
self-beautiful is said to be a reminiscence of its prenatal 
existence.  As to the precise forms in which the idea of beauty 
reveals itself, Plato is not very decided.  His theory of an 
absolute beauty does not easily adjust itself to the notion 
of its contributing merely a variety of sensuous pleasure, 
to which he appears to lean in some dialogues.  He tends 
to identify the self-beautiful with the conceptions of the 
true and the good, and thus there arose the Platonic formula 
kalokagathia. So far as his writings embody the notion of 
any common element in beautiful objects, it is proportion, 
harmony or unity among their parts.  He emphasizes unity in 
its simplest aspect as seen in evenness of line and purity of 
colour.  He recognizes in places the beauty of the mind, and 
seems to think that the highest beauty of proportion is to 
be found in the union of a beautiful mind with a beautiful 
body.  He had but a poor opinion of art, regarding it as a 
trick of imitation (mimesis) which takes us another step 
farther from the luminous sphere of rational intuition into 
the shadowy region of the semblances of sense.  Accordingly, 
in his scheme for an ideal republic, he provided for the most 
inexorable censorship of poets, &c.;, so as to make art as far 
as possible an instrument of moral and political training. 

Aristotle

Aristotle proceeded to a more serious investigation of the 
aesthetic phenomena so as to develop by scientific analysis 
certain principles of beauty and art.  In his treatises on 
poetry and rhetoric he gives us, along with a theory of these 
arts, certain general principles of beauty; and scattered among 
his other writings we find many valuable suggestions on the same 
subject.  He seeks (in the Metaphysics) to distinguish the 
good and the beautiful by saying that the former is always in 
action (`en praxei) whereas the latter may exist in motionless 
things as well (`en akinetois.) At the same time he had 
as a Greek to allow that though essentially different things 
the good might under certain conditions be called beautiful.  
He further distinguished the beautiful from the fit, and in 
a passage of the Politics set beauty above the useful and 
necessary.  He helped to determine another characteristic 
of the beautiful, the absence of all lust or desire in the 
pleasure it bestows.  The universal elements of beauty, 
again, Aristotle finds (in the Metaphysics) to be order 
(taxis), symmetry and definiteness or determinateness (to 
orismenon).  In the Poetics he adds another essential, 
namely, a certain magnitude; it being desir