Who defines aesthetics?

Aesthetics is a study of sensations and feelings that continuously get generated in us by objects. The sensation, more often than not, would be of the pleasurable sort. But even tearjerker movies, something hurtful or disgusting or painful, even that can cause intense enjoyment, intense feeling and emotional investment on our part, and therefore that can also qualify as a subject of aesthetics.

A very important question is whether the object itself yields the aesthetic response, or is it the subject and the particular situation that the individual is in. Even for the same person, depending on context, a film you absolutely hated at one point of time, at some other point when you were in a different emotional state, you may enjoy that very film.

And yet, not all non-beautiful forms can gain aesthetic currency. It probably also has to have some kind of an institutional stamp on it.