[Mad Dawg]

For better or for worse it’s been part of the Catholic lexicon since 1891 and “Rerum Novarum.”

[Calvin Locke]

Now that you mention it, I do recall reading about Catholic references a few months ago, but even with 12 years of Catholic education, It was still thirty years ago that I first heard it.

Perhaps the revival of the term was spurred on by JPII's crackdown on liberation theology priests (mostly in South America, iirc).