As for the extent to which the existing store of knowledge, and in particular the thoughts of other people who retain external ownership of their intellectual products, become, by virtue of the newflnn which they acquire through repeated expression, a special intellectual fgeistiges property of the individual who reproduces them and thereby give him (or fail to give him) the right to make them his external property in tum the extent to which this is so cannot be precisely determined, nor therefore defined in terms of right and the law.