Idea-Expression Divide or Idea-Expression Dichotomy.
Idea-Expression Dichotomy is embodied in Section 102(b) of the copyright code. Idea-Expression Dichotomy denies protection to the ideas which underlie copyrightable works. Only the original "expressions" contained in these works can actually receive copyright protection.
The first amendment provides that "Congress shall pass no law abridging the freedom of speech." The idea-expression dichotomy discharges copyright's first amendment duties because the application of copyright protection to expressions, but not to ideas, serves to prohibit only speech that is constitutionally valueless.
Intellectual property laws are generally designed keeping Idea-Expression Dichotomy in mind to protect the fixed expression of an idea rather than the fundamental idea itself.
Examples of Idea-Expression Dichotomy or Idea-Expression Divide
Copyright may not subsist in the idea of a man on an expedition, but may subsist in a book which follows that expedition.
Similarly, if the methods or processes described in a technical non-fiction work are patentable they may be the subject of various patent claims, whereas the fundamental underlying idea may not be. An adventure novel provides an illustration of the concept. Copyright may subsist in the work as a whole, in the particular story or characters involved, or in any artwork contained in the book, but generally not in the idea or genre of the story.
The idea-expression divide which is also referred to as
idea-expression dichotomy is a concept which explains the appropriate function of
intellectual property laws, which are generally designed to protect the fixed expression
or manifestation of an idea rather than the fundamental idea itself.
"Unlike a patent, a copyright gives no exclusive
right to the art disclosed; protection is given only to the expression of the idea, not
the idea itself." Mazer v. Stein, 347 U.S. 201, 217 (1954) - Idea-Expression