Blackstone in his Commentaries of 1767, in which the word copyright seems to have been first used, lays down the fundamental principles of copyright as follows: "When a man, by the exertion of his rational powers, has produced an original work, he seems to have clearly a right to dispose of that identical work as he pleases, and any attempt to vary the disposition he has made of it appears to be an invasion of that right. Now the identity of a literary composition consists entirely in the sentiment and the language; the same conceptions, clothed in the same words, must necessarily be the same composition; and whatever method be taken of exhibiting that composition to the ear or the eye of another, by recital, by writing, or by printing, in any number of copies, or at any period of time, it is always the identical work of the author which is so exhibited; and no other man (it hath been thought) can have a right to exhibit it, especially for profit, without the author's consent. This consent may, perhaps, be tacitly given to all mankind, when an author suffers his work to be published by another hand, without any claim or reserve of right, and without stamping on it any marks of ownership; it being then a present to the public, like building a church or bridge, or laying out a new highway." {Sidenote: Property by creation} There is nothing which may more rightfully be called property than the creation of the individual brain. For property (from the Latin _proprius_, own) means a man's very _own_, and there is nothing more his own than the thought, created, made out of no material thing (unless the nerve-food which the brain consumes in the act of thinking be so counted), which uses material things only for its record or manifestation. The best proof of _own_-ership is that if this individual man or woman had not thought this individual thought, realized in writing or in music or in marble, it would not exist. Or if the individual thinking it had put it aside without such record, it would not, in any practical sense, exist. We cannot know what "might have beens" of untold value have been lost to the world where thinkers, such as inventors, have had no inducement or opportunity thus to materialize their thoughts. {Sidenote: Are thoughts created?}