Catholic sociology may perhaps best be described as the mind of the Church on social questions. It is the application to social life (man in society) of the universal concepts of the faith. This is the first thing to be grasped about Catholic sociology, that it is essentially an inference from Catholic theology, and such as could be made therefore by anyone having a perfect knowledge of the faith.

As a matter of fact, however, the social implications of Catholic theology have been worked out at a very high level, so that there is in existence today a code of social principles which may be correctly described as the authoritative teaching of the Church on social questions. The corpus or main body of such teaching is to be found in various Papal encyclicals from the time of Leo XIII.

The nature and scope of Catholic sociology are well indicated in the following passage from Quadragesimo Anno in which Pope Pius XI asserts the right of the Church to pontificate on social questions: