In order to summarize the complaint the Church places at the feet of both capitalism and socialism, we can refer to the broad notion of economism. Economism is the reduction of all social concerns to the economic or material level, on the assumption that if the economy succeeds, all other social goods will be fulfilled as a result. While rarely acknowledged openly and adopted as such, this sort of economism is very common in practice. This is true even for those nations who would still explicitly deny materialism in its doctrinaire form.
Once economism becomes the ruling attitude of a society, its “image” of man is automatically defaced. St. John Paul II describes the historical development of this process as follows:
“This consistent image, in which the principle of the primacy of person over things is strictly preserved, was broken up in human thought, sometimes after a long period of incubation in practical living. The break occurred in such a way that labour was separated from capital and set in opposition to it, and capital was set in opposition to labour, as though they were two impersonal forces, two production factors juxtaposed in the same ‘economistic’ perspective. This way of stating the issue contained a fundamental error, what we can call the error of economism, that of considering human labour solely according to its economic purpose. This fundamental error of thought can and must be called an error of materialism, in that economism directly or indirectly includes a conviction of the primacy and superiority of the material, and directly or indirectly places the spiritual and the personal (man’s activity, moral values and such matters) in a position of subordination to material reality. This is still not theoretical materialism in the full sense of the term, but it is certainly practical materialism, a materialism judged capable of satisfying man’s needs, not so much on the grounds of premises derived from materialist theory, as on the grounds of a particular way of evaluating things, and so on the grounds of a certain hierarchy of goods based on the greater immediate attractiveness of what is material.”
 LE, 13.