"Are we there yet?": Just when is a work of art ... finished?

I decide, sometimes, that a painting I have been working on is "done" because it seems ... fresh.  Charles Hawthorne, a painter who established a school in Provincetown in 1899, once said that "a sketch has charm because of its truth, not because it is unfinished."  We are attracted to the new, emerging "thing" before we really know what it is because it says something we are straining to hear; but "charm" is not often what we are about.  I find myself working on two paintings right now that are trying to break through ... but I am not sure where they intend me to go, yet.  They are, decidedly, unfinished.

But what about works by ... Michaelangelo?  His "Saint Matthew," the only one of the commissioned apostles statues that he began (in 1504? 1505?) was intended for the Cathedral in Florence:

 

The statue is emerging from the marble; critics and artists have studied this statue for its clues to Michaelangelo's working methods.  The artist was unlikely to have thought this piece finished; his other work is so highly sanded and smooth, perfect, in fact.  And yet, I think this piece blows Hawthorne's statement wide open.  This is not "charm," but it is "truth." I think it stands on its own as a work of art, with the body twisting itself into an "S" shape and the block of marble stiff with resistance.  The tension here, the organic vs. the geometric forces, the rough vs. the polished, is palpable.

Then we can visit Rodin's "Torso (A study for Ariane without Arms)" from about 1905:

Clare Vincent writes (on the metmuseum.org website's Rodin page) that this torso offers us a glimpse into Rodin's process: "the deliberate breaking apart of sculptures in order to reassemble the parts in new ways."  We can see the breaks.  In some ways, then, this is a sketch. Rodin would not have considered it complete.  And yet, it is on show.  It is, to me, beautiful, its cracks and dents and breaks all asking the viewer to imagine as if we were to take the next steps. Where from here?

Matisse created a series of four massive sculptures, all of a woman, each with her back to us, between 1909 and 1930.  Each stage had been sculpted in clay before it was cast.  Below, "The Back III," from 1916:

 

This is part of an increasingly abstract progression; Matisse did, I believe, consider this a completed work.  I certainly do ... I think the presence here is significant.

So how can we tell when a work of art is complete?  We could say that if an artist is still looking, the work is unfinished.  But we could also say, as the audience,  that there might be another way to look at it. Even if you might agree that the original intent of the artist would have been to keep going, you have the right to agree ... if you can say ... where the work should go from here.