Marcel Duchamp's 'Nude descending the stairs' is the result of the desire for motion. Here he has also eliminated representative form. This avoids th… - Alexander Calder

The sense of motion in painting and sculpture has long been considered as one of the primary elements of the composition.

I started [in Paris, 1920's, making toys] right away, using wire as my main material as well as working with others like string, leather, fabric and wood. Wood combined with wire (with which I could make the heads, tails and feet of animals as well as articulating parts) was almost always my medium of choice. One friend of mine suggested that I should make bodies entirely of wire, and that is how I started to make what I called 'Wire Sculpture'. In Montparnasse, I became known as the 'King of Wire'.

As truly serious art must follow the greater laws, and not only appearances, I try to put all the elements in motion in my mobile sculptures.