invention was merely the application of the facts and the laws of nature, which are common property, was to speak like a lawyer rather than like a philosopher or a man of science. Whatever other distinctions may be insisted on between Copyright and invention, this, at any rate, will not bear a moment’s examination. It may have a colour of plausibility in the case of a poem, a play, or a novel, though even there it is not altogether sound. But literature includes history, science, philosophy, mathematics, and the like; and every book on these and most other subjects, so far as it has any value, is based entirely upon facts and laws which are no more the creation of the author than are the facts and laws on which an invention may be founded. In each case there is creation in the same qualified sense. Say that a man creates what he reveals, or what he proves, and the author and the inventor are equally entitled to be called creators. Say, on the other hand, with perhaps more accuracy, that to proclaim a previously unnoticed truth is only to announce what has all along existed in nature and nature’s laws, and some more modest title than creator must be assumed by author and inventor alike. The difference between the two cases is not a difference of principle, but of convenience. The thing created, either in the book or the machine, is the thought or the method; but property in a thought or a method is not what the law allows in either case, simply because it would be impossible to give an effect to such an enactment. What the law does is to lay hold of the most profitable mode of using the idea, and say that for a limited time no one but the originator shall be at liberty, in the one case, to print the book or a colourable imitation of it; or, in the other, to manufacture or use the machine or any colourable imitation of that. It is impossible, we think, to deny the abstract right of a real author or inventor, and more palpably impossible to deny it in the one case while you admit it in the other.