On the train to work this morning I finished reading Recognizing the Public Domain by David Lange (originally published in Law & Contemporary Problems, Autumn 1981), which in footnote 20 quotes from Carmen, The Function of the Judge and Jury in the "Literary Property" Lawsuit (42 Calif. L. Rev. 52, 57-59 (1954)) as follows:
Regardless of the variations of terminology occasioned by the limitations of the English language in treating with such evanescent abstractions, the cases generally exhibit a surprising uniformity of approach and conception. The courts wholeheartedly recognize that ideas, new or old, when once disclosed must be kept "free as air" for all to use. They recognize further that the vast accumulation of human experience, the character of man and his world in all its varying phases, and the relationships of each to the other and to other men and other things, not only in the general but the specific, are not and cannot become the "property" of anyone regardless of how they are expressed. These things are the universal heritage, the public commons, from which all may freely draw sustenance and which all may use as seems most satisfactory to them.
Well said.