There are different forms of ownership: first, private, as that of individuals, families, partnerships, or corporations; second, public or state, as the ownership of the state house, the highway, the Adirondack forest-reserve or the Erie Canal. These are equally effective as against the claims of outsiders, but the rights of those inside the circle of ownership differ. For example, the rights of one shareholder against another, or the rights of one member of a family as against another, are not the same as the rights against outsiders. Private property is the characteristic feature of our present industrial society, but it exists side by side with state property and with many intermediate grades between private and common property. Private property, while attacked on some sides, is usually accepted without question; but in this age of inquiry its origin should be examined, its limits and the reasons for them should be noted, and its purpose, faults, and effects should be set clearly before the judgment. [Sidenote: Various theories of property: Occupation] 2. _The older theories of the origin of private property are those of occupation, conquest, labor, natural rights, and law._ The theory of occupation is that property is based upon the priority of claim of one who finds wealth without an owner and appropriates it. This, to be sure, is a statement of what happens in the settlement of new countries, but it is not an explanation of the property rights that are arising every moment, nor does it give a logical reason for the continuance of ancient property rights. [Sidenote: Conquest] The same can be said of the conquest theory, the theory that property is based on force. It applies to the invasion of the Roman provinces by the barbarian tribes who divided the country and enslaved the population. But it rarely applies to present-day happenings and at its best it cannot, to modern minds, "justify" present property rights. [Sidenote: Labor] The labor theory, meeting some queries where others fail, is that ownership is based on production, on the right of a man to that to which his brain and his muscle have imparted value. It is evident that this test leaves without explanation or justification a great number of things that do exist and have existed as property. [Sidenote: Natural rights] The natural-rights theory is that property is necessary for the realization of the dignity of human nature. This, if true, would be not so much an explanation as a condemnation of private property as it has existed in most cases, as millions of men are in every land all but lacking in property, and inequality of possession is everywhere marked. This theory expresses, however, one of the worthy ideals of modern democracy. Although, in common with the various other "natural rights" theories, it must to-day be deemed too absolute and too individualistic, it contains a far-reaching truth, of which due account must be taken in our social philosophy.