"Let the working man and the employer make free agreements, and in particular let them agree freely as to the wages; nevertheless, there underlies a dictate of natural justice more imperious and ancient than any bargain between man and man, namely, that wages ought not to be insufficient to support a frugal and well-behaved wage-earner. #If through necessity or fear of a worse evil the workman accept harder conditions because an employer or contractor will afford him no better, he is made the victim of force and injustice.#"
It is called the Social doctrine of the Church; there's still Socialist parties in Europe and Latin America based on this concept.
The Papacy can be broken down into three categories:
1) absolute monsters who abused their power to try to destroy their enemies and take over the world
2) unqualified nincompoops who made no drastic changes or did anything to upset the status quo
3) revolutionary men of Christ who sought to bring justice, peace and love to the world.
The Catholic doctrine on economic justice is called distributionism--which is a sort if middle way between socialism and capitalism, the unique bit being that it advocates for the creation of a *very* strong government apparatus on the prevention and busting up of monopolies, cartels, combines and trusts.
>TFW Reddit learns that the Catholic Church has always advocated for true social justice and not some bastardized version which seeks to murder and steal from others to achieve that goal.
Look up something called "liberation theology". It's been branded "Christian Marxism" by critics. It's historically been huge in South America. When Benedict XVI stepped down (which is, in itself, almost unheard of for a Pope to do) I predicted that the next Pope would be from South America, and would steer the church in a much more leftist direction, ultimately probably being assassinated if he decided to go full Romero on us. That was before Francis, and so far it does indeed seem as though things are heading in that direction. I'm a big fan of Catholic social justice movements - the church has always been pretty "radical" in that way.
EDIT: A fundamental point of Catholic social teaching - so much so that it has its own Wiki article as well - is the "option for the poor". It emphasizes lifting and dignifying the poor.