Art rules the world. But what about the rules of art? In our current day and age, the general consensus seems to be that creativity, divine inspiration and art can never be bound by rules. Artists need to push the envelope, be ahead of the curve, and if there are any rules out there it is the artist's prerogative, if not God-given right, to break them.

But up to the early 20th century, artists did not have the complete artistic freedom that they are believed to enjoy today. They were bound by...