natural resources from the former inhabitants, who in turn had taken
them from other occupants, many centuries before. The conquest theory
applies, for example, to the invasion of the Roman provinces by
barbarian tribes who divided the country and developed the feudal
system based on land tenure. But it hardly applies to present-day
happenings, and at its best it cannot, to modern minds, "justify"
present property rights.

The labor theory, meeting some queries where others fail, is that
ownership is based on the act of production. It is declared that
every man has a right 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. Usually the basis of the labor theory
of property is declared to be each individual's natural right to the
results of his own labor, which claim is assumed to be an ultimate,
undebatable, axiomatic fact. However, that type of natural-right
doctrine, which makes no appeal to experience and results, is now
quite discredited in political science.

Another form of natural-rights theory is that property is necessary
for the realization of the dignity of human nature and every
individual has the natural right to self-realization. This theory
is, in a way, based on an appeal to experience, as to the effect of
property on human character, and it has the virtue of expressing one
of the ideals of modern democracy. Altho, in common with various other
"natural-rights" theories, it must be deemed too absolute and too
individualistic, it contains a far-reaching truth, of which due
account must be taken in our social philosophy.