Although the courts have considered and ruled upon the fair use doctrine over and over again, no real definition of the concept has ever emerged. Indeed, since the doctrine is an equitable rule of reason, no generally applicable definition is possible, and each case raising the question must be decided on its own facts. On the other hand, the courts have evolved a set of criteria which, though in no case definitive or determinative, provide some gauge for balancing the equities. These criteria have been stated in various ways, but essentially they can all be reduced to the four standards which have been adopted in section 107: (…) These criteria are relevant in determining whether the basic doctrine of fair use, as stated in the first sentence of section 107, applies in a particular case: "Notwithstanding the provisions of section 106, the fair use of a copyrighted work, including such use by reproduction in copies or phonorecords or by any other means specified by that section, for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright."

The specific wording of section 107 as it now stands is the result of a process of accretion, resulting from the long controversy over the related problems of fair use and the reproduction (mostly by photocopying) of copyrighted material for educational and scholarly purposes. For example, the reference to fair use "by reproduction in copies or phonorecords or by any other means" is mainly intended to make clear that the doctrine has as much application to photocopying and taping as to older forms of use; it is not intended to give these kinds of reproduction any special status under the fair use provision or to sanction any reproduction beyond the normal and reasonable limits of fair use. Similarly, the newly-added reference to "multiple copies for classroom use" is a recognition that, under the proper circumstances of fairness, the doctrine can be applied to reproductions of multiple copies for the members of a class.

The Committee has amended the first of the criteria to be considered—"the purpose and character of the use"—to state explicitly that this factor includes a consideration of "whether such use is of a commercial nature or is for non-profit educational purposes." This amendment is not intended to be interpreted as any sort of not-for-profit limitation on educational uses of copyrighted works. It is an express recognition that, as under the present law, the commercial or non-profit character of an activity, while not conclusive with respect to fair use, can and should be weighed along with other factors in fair use decisions. General Intention Behind the Provision:The statement of the fair use doctrine in section 107 offers some guidance to users in determining when the principles of the doctrine apply. However, the endless variety of situations and combinations of circumstances that can rise in particular cases precludes the formulation of exact rules in the statute. The bill endorses the purpose and general scope of the judicial doctrine of fair use, but there is no disposition to freeze the doctrine in the statute, especially during a period of rapid technological change.