Things and the classification of things: the first division.
 1We have spoken above of persons, the status of men and the law of persons; we  must now speak of things, dividing [them] into classes, for in that way a subject is  more clearly set forth. The first division into which things fall is this: some are  within our patrimony, some outside it. What things are within our patrimony will  appear adequately below. Outside our patrimony are sacred things and things  owned in common. Some are neither within nor without our patrimony, as rights  and servitudes, a usufruct, a right of passage [or] of driving beasts, a right of way  over or a right to conduct water over another man's land and other similar  arrangements. Servitudes are said not to be owned because they cannot be aliened  by themselves apart from the land. Praedial servitudes cannot be thought of as  having an existence of their own, and thus are taken not to exist, or to be extinguished,  when regarded separately, for a sleeve is taken no longer to exist as such  when [not]2 attached to a garment and a beam is taken not to be possessed when [not]  attached to a house. Nevertheless, these servitudes are not thought of as things  unowned, since [for them] possessors have an exception and those who do not possess  an action.3
A second division.
 4There is another, a second, classification of things, for some are corporeal, others  incorporeal.5 Corporeal are those that can be touched, [that is], immovables, as  land, an estate, or movables, whether animate, as animals and such, or inanimate.  Incorporeal things, such as rights, are those which can neither be seen nor touched,  as a right of way over another's land, a right to drive beasts or conduct water over  it and other such, which cannot be possessed only quasi-possessed.
A third division.
 6There is as well a third classification of things: some are common, others are public,  others are the property of the universitas; some belong to no one, others, acquired  for each by a causa of some kind, belong to individual persons.7
Some things are common.
 8By natural law these are common to all: running water, air,