"The Church's surprising lesson for partisans of big government is that the best tools for correctly ordering economic life are found in the choices of individual market actors. Because those choices are based not only on their preferences but also on their convictions, people's moral sensibilities—the extent to which they believe they have ethical obligations to each other—have a powerful and unavoidable effect on the shape of the economy. Contrary to what you might expect, Catholic social teaching suggests that this, not public policy, performs the first and most important regulatory function in a free society.
The popes of the last century have been clear that when they speak out against unregulated liberal capitalism, they're referring to a system in which all involved are concerned solely with their own material advantage and will happily sacrifice others in the pursuit thereof. Per the Catechism of the Catholic Church, "A theory that makes profit the exclusive norm and ultimate end of economic activity is morally unacceptable.""