ed society as we know it. The law of
property in the widest sense, including incorporeal property and the
growing doctrines as to protection of economically advantageous
relations, gives effect to the social want or demand formulated in
this postulate. So also does the law of contract in an economic order
based upon credit. A social interest in the security of acquisitions
and a social interest in the security of transactions are the forms of
the interest in the general security which give the law most to do.
The general safety, peace and order and the general health are secured
for the most part by police and administrative agencies. Property and
contract, security of acquisitions and security of transactions are
the domain in which law is most effective and is chiefly invoked.
Hence property and contract are the two subjects about which
philosophy of law has had the most to say.

In the law of liability, both for injuries and for undertakings,
philosophical theories have had much influence in shaping the actual
law. If they have grown out of attempts to understand and explain
existing legal precepts, yet they have furnished a critique by which
to judge those precepts, to shape them for the future and to build new
ones out of them or upon them. This is much less true of philosophical
theories of property. Their role has not been critical or creative but
explanatory. They have not shown how to build but have sought to
satisfy men with what they had built already. Examination of these
theories is an illuminating study of how philosophical theories of law
grow out of the facts of time and place as explanations thereof and
then are given universal application as necessarily explanatory or
determinative of social and legal phenomena for all time and in every
place. It has been said that the philosophy of law seeks the permanent
or enduring element in the law of the time and place. It would be
quite as true to say that it seeks to find in the law of the time and
place a permanent or enduring picture of universal law.

It has been said that the individual in civilized society claims to
control and to apply to his purposes what he discovers and reduces to
his power, what he creates by his labor, physical or mental, and what
he acquires under the prevailing social, economic or legal system by
exchange, purchase, gift or succession. The first and second of these
have always been spoken of as giving a "natural" title to property