Stoid:
Concerning my definition of art, my first inclination would be to start with a base such as the use of skill and imagination in the creation of aesthetic objects, environments, or experiences that can be shared with others. This, however, does not address the issue of found art. Some folks put forward that the act of identifying and presenting found art turns non-art into art. Thus we come to the business of anything an artist says is art supposedly being art, and since anyone can consider one’s self an artist, we come to the absurd position of everything being art. “That grain of sand at the bottom of the sea in the middle of the Atlantic Ocean? It must be art because I am an artist and I say it is art. Same goes for that fine artistic creation of mine which gets flushed every morning. I’m an artist, so it must be art.” Sorry, but I don’t buy into this school. I believe that there are people who are trying to expand the concept of art to include that which has not been previously considered art, and in many instances they have had success. This is a far cry from establishing that everything is art.
There are others, such as myself, who take a contextual approach. For example, when you say that art is something which is created to provoke a feeling or an idea, you are putting forth a contextual approach, for the audience cannot but help synthesize the impressions from the art with their existing views. My position is more along the lines of reader response, where the art is created as a result of the bringing together of both the artist’s work and the audience’s background. Thus without context, there is no art. This is why many works accepted as art within the art world are not considered to be art by those outside of the art world, for those on the outside may not have the background to provide enough of a context to permit a meaningful experience. In this sense, a work may be art for one person, but may not be art for another person simply due to a lack of context. As you can see, with my approach a lack of context negates the creation of art between the artist and the audience. An object, environment or experience can exist and not be art, but upon sufficient context, can then become art. The artist can not unilaterally claim to have created art. All the artist can claim is that the artist has created a work, and wait to see if art is created out of the interaction with the audience.
I am also quite comfortable in stating that there are negative boundaries which define art. For example, the skinned cat would fit within both your definition and my definition of art up to this point. I believe, however, that a positive definition is not sufficient. You say that art is something which is created to provoke a feeling or an idea, but I can carry that to an absurd extreme by wandering about shooting people in the guts. It would provoke feelings and ideas. Would it be art? No. It would be an atrocity of no artistic merit what so ever. I believe that just as art requires a context, part of that context must be a consideration of societal mores. It is one thing to test the limits of what society considers acceptable, and to try to expand those limits. This is central to the world of art in recent times. However, there are actions which are so far beyond the pale of societal acceptance that they entirely fail to be art. Mass slaughters in ancient Rome’s fora and mass guillotining in early republican France may once have provided popular spectacles, but if either were to happen in our society today, they would not be art, for despite clearly meeting all the positive definitions of art you and I have put forward, they are simply too far outside of our society’s contextualization of art. Times change, so what may be art in some societies may not be art in others.
Let’s try a mind experiment. Let’s say you are the director of a gallery, sitting at a long table with your entire family. The performance artist arrives, decrees that everything that evening will be art, then tells some nasty mother-in-law jokes, and asks you, “Is it art?” It easily fits the positive definitions we have put forth, so you say “Yes, it is art.” The performance artist then spits on your mother-in-law, and asks you if it is art. It fits all the positive definitions (and is probably a good thing in general anyway 
), so you say, “Yes, it is art.” Then the performance artist breaks the old dear’s arm, and asks you if it is art. You say, “Yes, it is art, because it meets all the positive definitions,” but you also say that, “It is both morally and legally wrong.” The performance artist then breaks her neck, leaving her permanently a quadriplegic. Once again, you are asked if it is art. What do you reply? The performance artist continues moving up the table, either maiming or killing each and every member of your family, and each time he asks you, “Is it art.” And each time it fits the positive definitions of art. At what point do you say, “No. It is not art.” Think this through. Imagine that it really is your family up there, and this is actually happening. In all honesty, could you keep saying “Yes, it is art,” or at some point would you say, “No, it is not art. It is an atrocity and nothing more.” Or would you continue to say “Yes, it is art because you are the performance artist and you have decreed that it is art.”
Or worse yet, try another mind experiment. I expect you are familiar with the artist Dolcett. Some will look at the illustrated stories and laugh, some will be turned on, and I expect most will be thoroughly revolted. But as long as the illustrated stories remain only that, a claim for art may be made in some quarters. Now imagine that rather than fiction, the illustrated stories are performance art, and you and your family are participants. Surely you can not seriously contend that such activity could be considered art?
By now I expect that most would agree with me that not everything is art, and that some activities are so beyond the pale that they can not be considered to be art, despite meeting all of the positive definitions of art. In short, art is also negatively defined by what is not art.
I believe that at the very least, when the creation of aesthetic objects, environments, or experiences directly and deliberately causes real, significant and non-consensual pain and death, then it is not art. How broad this negative aspect of the definition of art may be is just as subject to testing as the positive definitions. If a person were skinned alive, it would not be art. Now how about a cat? From my context, which includes a world view which places significant value on animals, there is no art, for the action is beyond the pale. For others who hold animals in less regard, perhaps the action falls close enough to the existing contextual envelope that art is created.
From my definition of art, which includes both positive and negative qualifiers, the skinning of the cat is not art. And I truly hope that our society never turns to accepting such acts as art.