Quote Originally Posted by mannbro View Post
Picasso's cubism wasn't invented to break rules, it was created to expand in the ideas of perspective to take the viewer furtherin to the subject through exploring several angles and points of view simultaneously.
picasso didn't invent cubism at all.
others were similar things before ... he made it famous

what these people you mention did was stand outside convention, you are right they didn't break rules
they created new rules because the rules that existed did not relate to what they were doing.