Taste is an abstract, ineffable, unstable thing. A listener to music or reader of a book cannot truly tell if they will enjoy something before they experience it; pleasure in a piece of art is never guaranteed. So when encountering an artwork, we immediately evaluate it by some set of mental principles, and, hopefully, find the beauty in it, feel affirmed, even if we can’t quite describe what that beauty is or how exactly we determined it in the first place.