A general copyrighted protection of ideas would not only endanger the freedom of science and art, but also impede the whole intellectual life in an intolerable way. Copyright therefore does not protect pure ideas, concepts, doctrines and theories as such. Only in their tangible form of presentation they become subject of the copyright protection. For example not the content of quantum theory of Max Planck as such is protected by copyright, but only the version precisely formulated by Planck. Likewise only a concrete cartoon with parodist content may enjoy copyright protection, but not the bare idea to lampoon cultural activities.