Immanuel Kant describes this difference to be the rational aspect of man which also makes hime free to choose, to create, and to be an individual. Man possesses the capability of rationality while nature remains instinctive. Nature does not create things as representation of the world. It is only what it is, not able to be conscious of itself and of the other. It is full, containing forms and materials, not able to create forms outside itself nor even conceive anything other than itself.
Man is rational.
He separates himself from the world, generalizing and creating representation for things he sees in the world. This is art in a primary definition, neither complete nor meaningful. When one sees a work of art, one intuitively realizes that it is not actually the thing which it attempts to represent. The statue of a man is not a man, the painting of a tree not actually a tree. Nature imposes the form of a flower upon material and produces a flower, that is the essence of nature's creative processes-not man's creative processes.