That the inventor has a right of use or property in his invention we do not dispute; what we dispute is his _exclusive_ right. To give one inventor such a right is to subvert the principle by denying the right of other inventors, who may be as original, and have worked as hard, and spent as much, but who, owing to a desire to perfect their achievement a little more, or because they live in the provinces,—a day’s journey further off,—come some hours behind, and so are only second or third applicants for the coveted privilege. The State ought not, and cannot in strict justice, give a right of exclusive property; that is, power to meddle with others, and forbid them to use their valuable knowledge; except in cases where _common_ use and enjoyment would diminish public wealth or harm a previous possessor. If the land of England were constituted common property, its productive value would be lessened, and the present possessors would be harmed; therefore, it legitimately is property. Knowledge may be, with the greatest benefits to mankind, common. God has drawn this distinction between things material or measurable (in which classification I include labour), and things mental: between land, ploughs, and the like, and the art or knowledge how to manage or make them,—that the one cannot be appropriated, and the other cannot be unappropriated, without loss to our race. _En passant_, do we conform to the spirit this constitution of nature may be held to commend to man? I will not detain you by controverting the arguments of those plausible reasoners who class Patent-right with Copyright. Both, indeed, are creations of enacting law. But there is this obvious and broad distinction between them: that to grant exclusive privileges to an author interferes with nobody else’s compositions, whereas to grant them to an inventor continually conflicts with what others have done and are doing. Nor shall we spend time in discussing the _merits_ of inventors. These, we allow, may be great, and deserve public acknowledgment. What ought rather to be discussed is the _kind_ of acknowledgment that is most expedient. At present a very primitive mode of rewarding inventors is alone the rule—monopoly. In old times, when political economy, like the other sciences, was unknown, it was the easy, but at the same time costly, way of endowing a court favourite to grant him an exclusive right to sell or make some commodity. When, in the beginning of the seventeenth century, all other monopolies were prohibited by law, those in favour of introducers of _new manufactures_ were spared. This exception has been found or made so expansible, that it is ruled to extend to minute processes or instruments in existing trades, so that what was intended to promote manufactures is now too frequently a hindrance. Thus the avowed object of the exception, public good, is on the whole counteracted. What we maintain is, that, admitting the monopoly attains to some extent that