The "Art is in the eye of the beholder" argument is interesting. Let's use the case of photography, rather than Art since we all care about photography. As a photographer, I have come to where I am in this pursuit, hobby, pasttime, work, whatever word you need to insert here, insert it-- I have come to it as both a learner, who appreciates the work of others, who has been influenced by other photographers, or even painters, or even just by walking around or growing up in the world that is my own little world. I am influenced. So in that sense of being a photographer, I am part of a larger milieu, or if I really have looked at a lot of other photography, I could even say I am part of a tradition, or a style of photography. I may even have heroes who give me the inspiration to rise up to that level of work. As a part of the overall world of photography, as a consumer of it, yes, art is what I behold to be art, based on how I havebeen influenced. If I have never seen a Winogrand photo, and one day I see a few of them and I like them very much, though I don;'t know why because up to now, my ideaof photography is landscape masterpieces, then how to explain what art is? Is it inside me, or is it outside. Or both?
On the other hand, after some time, I start to develop my own way, my own style, my own thing with photography. After a while I see my own shots have things in common. I start to see I shoot particular subjects, or when I am photographing, let's say the street turns me on and excites me, or portraiture or landscape or wildlife or sports or homelessness. I start to follow my own intuitions and instincts, and I also start working to make my technique better.
Again, when I look at many many of the photos on this site, I see there is a lot of aspiration to become better. There is a lot of care that goes into shooting. Even many of us who disavow ambition as far as commerce, or as far as giving a hoot if we are artists or monkeys-- there is this desire to learn, to do good work. There is, in other words, an interplay between being part of the tradition of photography and of doing our own thing.
I would say that it's more accurate to say Art is in the Work of the Beholder.