Laudator Temporis Acti

Percy Bysshe Shelley, letter to Thomas Love Peacock (January 26, 1819):

I now understand why the Greeks were such great poets; and, above all, I can account, it seems to me, for the harmony, the unity, the perfection, the uniform excellence, of all their works of art. They lived in a perpetual commerce with external nature, and nourished themselves upon the spirit of its forms. Their theatres were all open to the mountains and the sky. Their columns, the ideal types of a sacred forest, with its roof of interwoven tracery, admitted the light and wind; the odour and the freshness of the country penetrated the cities. Their temples were mostly upaithric; and the flying clouds, the stars, or the deep sky, were seen above. O, but for that series of wretched wars which terminated in the Roman conquest of the world; but for the Christian religion, which put the finishing stroke on the ancient system; but for those changes that conducted Athens to its ruin—to what an eminence might not humanity have arrived!

upaithric, from ὑπό (under, beneath) and αἰθήρ (sky, heaven).