There are a few divisions in the ethereal philosophy of the purpose of art. One division is social need, whether art is to address or comment upon society vs. art that does not, has no message or forms a personal commentary. I can attest that as soon as art has some sort of meaning for message, it feel somehow weaker, that the delicate balance, ideally 50:50, between artist and audience is harmed.
I don't believe in the validity of the term "art for art's sake", that is the existence of art that means nothing or fulfils no need. Art will always be about something and always contain some message. Art is communication, a communication between the artist and viewer. A cloud in the sky doesn't communicate much of a message, but a viewer, by rote of being half of every communicative act, can still interpret messages within it.
There is meaning and feeling in every act of life, so it is impossible to create meaningless art, but it is a bad artist that forces the audience to provide it all. If a tree falls over before an audience, and it is considered an artistic act (perhaps Duchamp was in present and the act took place in a museum!) then they may interpret it in myriad ways: a sign of deforestation? The artist must at least provide some guidance. Perhaps, a simple title 'Triumph of the Loggers' is all that is needed.
Art may have a meaning, but this is different from an address of the needs, or commentary of, society at large. A direct message always has connotations of the preacher or advertising or propaganda, a third-party sharing of information. It is the inaccuracy of this message, the inauthenticity and the inevitable, even if accidental, pepper of lies that harms such art.
The problem with social art, like gossip or any social commentary, is that is is by necessity second hand information; the artist guesses about the ideas and feelings of a group, and conveys these to another group. The problem is that ultimately, we can never know what another group, or another individual, is actually feeling or experiencing, so any form of expression via this indirect route will necessarily have an element of falsehood, which, though not disastrous, will always harm the artwork; it will always be worse than art with more truth.
To maintain the purity of its message, the ideal art should be about the personal communication of the feelings and ideas of the artist alone to the viewer alone. Even art for a wide audience should ideally communicate to individuals on a personal basis. The artist can comment best on social issues by commenting on the effects of society upon the artist, and communication should aspire to a harmonious balance between artist and audience.
