attested from 1878, in vogue 1881, from Greek aisthetes "one who perceives," from stem of aisthanesthai "to perceive (by the senses or by the mind), to feel," from PIE *awis-dh-yo-, from root *au- "to perceive." Or perhaps from aesthetic on the model of athlete/athletic. The idea is somewhat older than the word. Aesthetician "professor of taste" is from 1829; aestheticist is from 1868.
1. Properly, one who cultivates the sense of the beautiful; one in whom the artistic sense or faculty is highly developed; one very sensible of the beauties of nature or art.—2. Commonly, a person who affects great love of art, music, poetry, and the like, and corresponding indifference to practical matters; one who carries the cultivation of subordinate forms of the beautiful to an exaggerated extent: used in slight contempt. [Century Dictionary, 1897]
I want to be an aesthete,
And with the aesthetes stand;
A sunflower on my forehead,
And a lily in my hand.
[Puck, Oct. 5, 1881]