Is an artwork complete without it being seen by an audience? Is it even art without an audience?

A person can duct-tape a banana to the wall of a cave where it remains visible only to bats. Does that make them an artist? Does that make the act artistic? What do you think? 

I believe that art is, at its core, communication- two way communication. Artists have a message or a vision and seek to share it. At the receiving end, the audience views and interprets the message. Only at that point does it complete its development. Artist Teresita Fernandez says that it is an unspoken request that the viewer participate. "I always think of the viewer as completing the circuit of meaning in the work." Artist Liz Deschenes calls it "viewer agency."

In the case of my own works of art, there is an overt invitation. If viewers let my works of art look at them, there are discoveries- quotes and maps and images half-hidden. I prefer to think that the messages are thought-provoking, not didactic. A quote that you find might cause a corresponding thought that informs the holistic perception of the composition. I have intention, but I can't control how my works are perceived. I can invite, but I can't ensure that the the audience will participate. It is the viewers who stay with the work, and let the art look at them, who make the composition complete.

Art is completed by the viewer.