Before photography existed, things were simpler. Art was made by trained artists. A painting was made with intent, there was no such thing as an accidental painting. A dog could not paint Mona Lisa. Ants on the page could not accidentally form the notes of a moving piano concerto. Art was always made with intent.
With photography as an art, things became suddenly murkier. A camera left on a table, nosed and worried at by a dog, takes a photograph. Click. Is that photograph good? Probably not, but it could be. What if that photograph happens to duplicate in all important ways, a well known and generally agreed upon to be great photograph? Is the dog's photograph also great? If you say no, then what is the art? Is it all intent, no piece? This way lies conceptual art, and you wind up with garbage nailed to the wall next to an essay, which produces no emotional response beyond a vague sense that this is a scam. Still, it's a theory.
Maybe art is the combination of intent and the piece, somehow? Well, what if we lose the provenance of a piece, say, a painting. Is it art now, or merely paint smeared on a surface? This seems unsatisfying. The art world certainly deals with this regularly when forgeries are revealed. Embarrassingly, the work is suddenly much cheaper, and it's badly done and amateurish through some strange alchemy that nobody understands but everyone agrees with because the alternative is that Vermeer wasn't all that after all.
What if I take the accidentally-great photograph from the dog, and write up an essay claiming that I shot it, with intent? Is this thing art?
These sorts of questions lead to madness and absurdity. While one can construct some sort of coherent position in most variations, most of the positions admit absurd consequences. Easier and more aligned with what the common man thinks of as art to simply drop the intent component, and accept that accidental art is possible. The art resides entirely in the piece. If it looks like art, if it sounds like art, it's art. We don't need an essay to know it's good. We don't need to authenticate the artist to know the piece is good. We don't have to shamefacedly adjust a piece from good to bad when it turns out to be fake. We can still love it and appreciate it, we simply don't have to pay as much for it now we know it to be a superb forgery.
A consequence of this theory is that a mere snapshot can be art. We need not postulate a fantastically lucky dog, we need only a tourist with an intuitive grasp of form, a little luck, and a lot of snapshots. Some are offended at the idea of some schmuck making art without trying. Get over it. If it moves you, it doesn't matter what the intent was, it moves you. That cannot be denied, it is tautological. If you want to try to hold the line and claim that while the piece is moving, it is not art, well, more power to you. We part ways here.