For some, Marxism remains essentially the active practice of class struggle. Experiencing the ever present and continually renewed force of the relationships of domination and exploitation among men, they reduce Marxism to no more than a struggle-at times with no other purpose-to be pursued and even stirred up in permanent fashion. For others, it is first and foremost the collective exercise of political and economic power under the direction of a single party, which would be the sole expression and guarantee of the welfare of all, and would deprive individuals and other groups of any possibility of initiative and choice. At a third level, Marxism, whether in power or not, is viewed as a socialist ideology based on historical materialism and the denial of everything transcendent. At other times, finally, it presents itself in a more attenuated form, one also more attractive to the modern mind: as a scientific activity, as a rigorous method of examining social and political reality, and as the rational link, tested by history, between theoretical knowledge and the practice of revolutionary transformation. Although this type of analysis gives a privileged position to certain aspects of reality to the detriment of the rest, and interprets them in the light of its ideology, it nevertheless furnishes some people not only with a working tool but also a certitude preliminary to action: the claim to decipher in a scientific manner the mainsprings of the evolution of society.
While, through the concrete existing form of Marxism, one can distinguish these various aspects and the questions they pose for the reflection and activity of Christians, it would be illusory and dangerous to reach a point of forgetting the intimate link which radically binds them together, to accept the elements of Marxist analysis without recognizing their relationships with ideology, and to enter into the practice of class struggle and its Marxist interpretations, while failing to note the kind of totalitarian and violent society to which this process leads. (Papal Writings, 14 May 1971).