Metaphysical theories of property are part of the general movement that replaced seventeenth-and eighteenth-century theories of natural rights, founded on the nature of the abstract man or on an assumed compact, by metaphysical theories. They begin with Kant. He first sets himself to justify the abstract idea of _a_ law of property--the idea of a system of "external _meum_ and _tuum_." Here, as everywhere else, he begins with the inviolability of the individual human personality. A thing is rightfully mine, he says, when I am so connected with it that anyone who uses it without my consent does me an injury. But to justify the law of property we must go beyond cases of possession where there is an actual physical relation to the object and interference therewith is an aggression upon personality. The thing can only be mine for the purposes of a legal system of _meum_ and _tuum_ where I will be wronged by another's use of it when it is not actually in my possession. This raises in the first instance the question "How is a merely juridical or rational [as distinguished from a purely physical] possession possible?" He answers the question by a metaphysical version of the occupation theory of the eighteenth century. Conceding that the idea of a primitive community of things is a fiction, the idea of a logically original community of the soil and of the things upon it, he says, has objective reality and practical juridical reality. Otherwise mere objects of the exercise of the will, exempted therefrom by operation of law, would be raised to the dignity of free-willing subjects, although they have no subjective claim to be respected. Thus the first possessor founds upon a common innate right of taking possession, and to disturb him is a wrong. The first taking of possession has "a title of right" behind it in the principle of the original common claim to possession. It results that this taker obtains a control "realized by the understanding and independent of relations of space," and he or those who derive from him may possess a parcel of land although remote from it physically. Such a possession is only possible in a state of civil society. In civil society, a declaration by word or act that an external thing is mine and making it an object of the exercise of my will is "a juridical act." It involves a declaration that others are under a duty of abstaining from the use of the object. It also involves an admission that I am bound in turn toward all others with respect to the objects they have made "externally theirs." For we are brought to the fundamental principle of justice that requires each to regulate his conduct by a universal rule that will give like effect to the will of others. This is guaranteed by the legal order in civil society and gives us the regime of external mine and thine. Having thus worked out a theory of _meum_ and _tuum_ as legal institutions, Kant turns to a theory of