Art is more than an idea, more than a  concept, even more than a way of expression. Art means to be able to manifest the feeling of life.  When it is contemplated as something that carries in itself- no matter what it is- and which always glorifies life in so many ways, as life can be in its infinity.
It is only needed to contemplate and the dynamics, the interaction between the elements with one or more senses will be recognized.  Since altogether or in its complexity or maybe in its simplicity, express something that is beyond its own image or representation.
Art, in order to be Art, has to express and does express itself as a river that has no end. Then, we will be able to see and understand the reason  because Art will guide us for a path of constant satisfaction.