"[T]he author's consent to a reasonable use of his copyrighted works ha[d] always been implied by the courts as a necessary incident of the constitutional policy of promoting the progress of science and the useful arts, since a prohibition of such use would inhibit subsequent writers from attempting to improve upon prior works and thus . . . frustrate the very ends sought to be attained." Ball 260. Professor Latman, in a study of the doctrine of
fair use commissioned by Congress for the revision effort, see
Sony Corp. of America v. Universal City Studios, Inc., 464 U. S., at 462-463, n. 9 (dissenting opinion), summarized prior law as turning on the "importance
550*550 of the material copied or performed from the point of view of the reasonable copyright owner. In other words, would the reasonable copyright owner have consented to the use?" Latman 15.
[3]