Except that things in the common culture should be able to be built upon, and expanded. I do need not seek out the estate of Sir Arthur Conan Doyle if I should

Except that things in the common culture should be able to be built upon, and expanded. I do need not seek out the estate of Sir Arthur Conan Doyle if I should desire to write a Sherlock Holmes book. It has become part of the common culture. Similarly, I should not need permission to make my own animations involving Mickey Mouse, Felix the Cat, Betty Boop, Popeye, Superman, or any other of the creations from the early 20th century. It is not only the artificial scarcity of creative works that makes lengthy copyright so obscene, but also the inability to build upon earlier works.