This paper explores the possibility of extending Locke’s theory with respect to tangible property so that it might offer a feasible theoretical basis for intellectual property too. The main conclusion is that such an attempt must fail. Locke’s theory comes in three parts: a general justification of property which serves to explain why assets ought to be under the exclusive control of individuals; a positive method of private appropriation whereby an individual acquires a prima facie exclusive claim to previously commonly (...) held natural resources; and third, a negative requirement that other individuals’ crucial interests are not harmed by such an appropriation. For each of these, the difficulties involved in applying that part of the theory to the sphere of ideas are discussed, and a central aspect of intellectual property that raises the problems of application is highlighted. (shrink)