This paper discusses the fair use doctrine added to the Copyright Revision Act, Public Law 94-553 (October, 1976). Fair use, an exception to the exclusive rights of copyright, is an assurance to the public of reasonable access to its heritage as guaranteed by the First and Ninth Amendments to the Constitution. Several important cases are described as illustrations of how the concept has been interpreted in the past. According to this paper, the doctrine cannot be frozen in statute beyond a broad explanation of what fair use is and the statement of some criteria applicable to it. The law states that the courts must be free to adapt the doctrine to specific cases. Explanatory footnotes provide additional information on the topic. (MAI)