Ad Petri Cathedram §42

⁴² As a matter of fact, the distances which separate the classes of society are shrinking. Since it is no longer a matter merely of "capital" and "labor," the number of classes has multiplied, and all of them are readily accessible to all men. Anyone who is diligent and capable has the opportunity to rise to higher levels of society. As for the condition of those who live by their daily toil, it is consoling to note that recently undertaken improvements in working conditions in factories and other places of employment have done more than give these workers a greater economic value; they have made their lives nobler and more dignified.