One of the most important characteristics that give meaning to art is radiance. Anyone can have ideas, but it's how well made something is that counts, and something is well made when it reflects the radiance of quality.
Great artists create great art when they transfer the light and space of the imagination through their medium. When this happens an idea is given a life of its own. This is the moment when something is well made, when the head, the heart and the hands work as one.
An author has to find the right words to turn an idea into life so it can become literature and if a song is badly performed then the sounds will not collect into music. If a sculpture is poorly constructed then its presence will not vibrate to the sculptor's vision. Painting and drawing have many forms of expression, but their lasting value is that light and space are present within the image.
What about an emotional response to an image regardless of how well made it is? A crucifix for example can inspire such a response to a devout Christian, even if it is crudely made, but is the cross art? A team banner can inspire sports fans but is the banner art or a slogan that has an emotional impact? Is an emotional impact enough?
If subject matter is the art, then the films of Alfred Hitchcock would be automatically bad because his films are primarily concerned with murder - a bad idea. Horror would also fit into the same category but there are great films and stories about murder and horror because they are well made, and others that lack quality because they are poorly made.
When we are engaged with a great work of art the sensation that we are looking at something amazing can be experienced. The quality of excellence imbues the work, but this is because what we are experiencing is well made and not because the idea or subject matter is noble or fascinating.
The radiance of light and space goes beyond ideas, techniques, narratives and materials, it is the reality of things. It's why a small radiant work of art can have more art in it than works that address important subject matter but be lacking in life