美國學生藝術史（英漢雙語版 上下冊）

If you will look at the picture called “Bird in Space” you will see an example of non-realistic sculpture. You can see that it doesn't look like a bird. But it does give the idea of flight. The flight of a bird depends upon wings and this sculpture seems to be all wing. At least most people think it looks wing-like. It is a smooth streamlined wing shape. Constantin Brancusi, its sculptor, carved into it no feathers, no body, no head or tail of a bird. Some people think that a piece of sculpture called a bird should look like a bird. In this sculpture, however, the flight of a bird, not the bird itself, is the important idea.