§ 153. Kinds of Property.
All property is, as we have already seen,[[409]] either corporeal or incorporeal. Corporeal property is the right of ownership in material things; incorporeal property is any other proprietary right in rem. Incorporeal property is itself of two kinds, namely (1) jura in re aliena or encumbrances, whether over material or immaterial things (for example, leases, mortgages, and servitudes), and (2) jura in re propria over immaterial things (for example, patents, copyrights, and trade-marks). The resulting threefold division of property appears in the following Table:—
| Property | Jura in re propria | Material things | Land | Corporeal property |
| Chattels | ||||
| Immaterial things | Patents | Incorporeal property | ||
| Copyrights | ||||
| Trade-marks | ||||
| &c. | ||||
| Jura in re aliena | Leases | |||
| Servitudes | ||||
| Securities | ||||
| &c. | ||||
§ 154. The Ownership of Material Things.
The owner of a material object is he who owns a right to the aggregate of its uses. He who has merely a special and definitely limited right to the use of it, such as a right of way or other servitude, is not an owner of the thing but merely an encumbrancer of it. The definition, however, must not be misunderstood. Ownership is the right of general use, not that of absolute or unlimited use. He is the owner of a thing who is entitled to all those uses of it which are not specially excepted and cut off by the law. No such right as that of absolute and unlimited use is known to the law. All lawful use is either general (that is to say, residuary) or specific, the former being ownership, and the latter encumbrance.
The limits thus imposed upon an owner’s right of use are of two kinds. The first constitute the natural limits of ownership. They are the various applications of the maxim: Sic utere tuo ut alienum non laedas—a legal principle whose function it is to restrain within due bounds the opposing maxim that a man may do as he pleases with his own. In the interests of the public or of a man’s neighbours many uses of the things which are his are wholly excluded from his right of ownership.
The second class of restrictions upon an owner’s right of use consists of those which flow from the existence of encumbrances vested in other persons. These are artificial limits which may or may not exist. My land may be mortgaged, leased, charged, bound by restrictive covenants, and so on, yet I remain the owner of it none the less. For I am still entitled to the residue of its uses, and whatever right over it is not specifically vested in some one else is vested in me. The residuary use so left to me may be of very small dimensions; some encumbrancer may own rights over it much more valuable than mine; but the ownership of it is in me and not in him. Were his right to determine to-morrow in any manner, my own, relieved from the encumbrance which now weighs it down, would forthwith spring up to its full stature and have again its full effect. No right loses its identity because of an encumbrance vested in some one else. That which is a right of ownership when there are no encumbrances, remains a right of ownership notwithstanding any number of them.
Inasmuch as the right of ownership is a right to the aggregate of the uses of the thing, it follows that ownership is necessarily permanent. No person having merely a temporary right to the use of a thing can be the owner of the thing, however general that right may be while it lasts. He who comes after him is the owner; for it is to him that the residue of the uses of the thing pertains. It is to be understood, however, that by a permanent right is meant nothing more than a right which is capable of lasting as long as the thing itself which is its subject-matter, however long or short that duration may be.
Even as the generality of ownership involves its permanence, so its permanence involves the further essential feature of inheritance. The only permanent rights which can be owned by a mortal man are those which can be handed down by him to his successors or representatives on his death. All others are temporary, their duration being necessarily limited to the lifetime of him in whom they are vested. The right of ownership, therefore, is essentially an inheritable right. It is capable of surviving its owner for the time being. It belongs to the class of rights which are divested by death but are not extinguished by it.
Summing up the conclusions to which we have attained, we may define the right of ownership in a material thing as the general, permanent, and inheritable right to the uses of that thing.[[410]]