Nature therefore is an action of God, and art the reaction of man. Art is divided into two classes: imitation (copying), and production (improving and improvising). The first wave of the artistic impulse is to imitate what he admires, and in this there are two tendencies that the artist shows, to copy and to improve. There is one artist who is more capable of copying, another of improvising. The skill in both aspects is equally great. To copy nature fully is beyond human capacity, and the greater an artist is in his art, the better he can copy nature. To copy nature, not only a keen observation but a deeper insight into the object before him is necessary.