Populorum Progressio was written by Giovanni Battista Montini, better known as Pope Paul VI. He wrote this treatise in 1967 as a response to the urgent needs he saw all over the world (such as hunger, disease, poverty, and lack of education), especially in the undeveloped nations.
The Pope discusses the duality of progress: while it has brought technology, advancement, and the Gospel of Christ to the dark places of the world, it has also advanced immorality and cultural corruption.
Left to itself [this kind of activity] works rather to widen the differences in the world's levels of life, not to diminish them: rich peoples enjoy rapid growth whereas the poor develop slowly. The imbalance is on the increase: some produce a surplus of foodstuffs, others cruelly lack them and see their exports made uncertain.
In other words, positive changes are also always coupled with negative consequences. With that in mind, Pope Paul VI suggests that all development, especially in undeveloped countries, should be done intentionally and in a holistic way; that is, concern should be given to all aspects of man, not just his physical being.
What he calls on the world to do, in essence, is to share goods, wealth, and resources equally throughout the world. He believes competition (capitalism) only increases the wealth of the rich while leaving everyone else even poorer. He advocates that wealthy nations must immediately share their wealth with less developed nations, through a kind of world fund, to ensure that these underserved people be given the opportunity to advance. The Pope believes education is essential for all people, as well.
He also warns the developing nations that this kind of international help is only a temporary fix for their immediate problems; each country must assess and take responsibility for identifying the kind of help which will benefit its people without creating dependency.
The Populorum Progressio is a document which advocates social justice and universal charity, and Pope John VI claims the need is urgent. He clearly states that any physical assistance must be coupled with moral and spiritual assistance, as well. It is not enough for a man just to feed his body; he must also feed his soul. The same is true, says the Pope, of countries and people on an international level.