The idea-expression dichotomy – also known as the “merger” doctrine – is a fundamental principle in copyright law that distinguishes between the underlying ideas or concepts contained in a creative work and the specific expression or form in which those ideas are presented. This principle asserts that copyright protection extends only to the expression of ideas and not to the ideas themselves. In other words, copyright protects the particular way in which an idea is expressed, rather than the idea or concept, itself. This means that while someone’s original expression of an idea may be protected by copyright, others are free to express the same underlying idea in their own way, as long as they do not copy the specific expression of the original work.
The idea-expression dichotomy helps strike a balance between encouraging creativity and innovation while also fostering the free flow of ideas and allowing for further development and expression. It prevents monopolies on ideas and ensures that multiple creators can explore and express similar concepts in their own distinct ways. Courts and legal systems often grapple with determining the appropriate boundaries between protected expression and unprotected ideas on a case-by-case basis.
The Supreme Court addressed the idea-expression dichotomy in its landmark decision in Baker v. Selden, in which the court held that a bookkeeping system created by Selden and described in his book was a method or process that fell outside the scope of copyright protection. The court reasoned that while copyright protects original expression, it does not extend to ideas, procedures, systems, or methods of operation. The court concluded that Selden’s book was merely a description of a useful art or process, which could not be monopolized by copyright.