An interesting development in the Western world was the introduction of the idea of light and shade into painting. This was not applied by the ancient artists, and it brought a new life to the world of art and made art more natural. But in modern Western art it often happens that an artist gets hold of an idea and thinks that it is the only idea there is and that there is nothing else besides it. He does not realize that any idea is a part of other ideas, and that many ideas together will make a whole. This has resulted in artistic movements such as cubism, which is derived from a certain impression one may get from the light. Light strikes out in straight" lines and forms angles; and so these artists wanted to paint all the different planes of their pictures in angles. They painted as if the whole world was made like that, in angles.