3 Lamenting this unhappy state of things from our innermost heart, We are compelled as by a certain necessity to express, according to our weakness, the same words that came from the love of the Most Sacred Heart of Jesus, crying out in like manner: "I have compassion on the multitude" ( Mark viii. 2). But, indeed, the root itself from which this most unhappy state of things arises is yet more to be lamented; for if that judgment of the Holy Spirit, proclaimed by the Apostle St. Paul, "the desire of money is the root of all evils," was always in close agreement with the facts, this is more than ever true at the present time. For is not that avidity for perishable goods which was justly and rightly mocked, even by a heathen poet as the execrable hunger of gold, " auri sacra fames "; is not that sordid seeking for each one's own benefit, which is very often the only motive by which bonds between either individuals or societies are instituted; and, lastly, is not this cupidity, by whatsoever name or style it is called, the chief reason why we now see, to our sorrow, that mankind is brought to its present critical condition? For it is from this that come the first shoots of a mutual suspicion which saps the strength of any human commerce; hence come the sparks of an envy which accounts the goods of others a loss to itself; hence comes that sordid and excessive self-love which orders and subordinates all things to its own advantage, and not only neglects but tramples upon the advantage of others; and, lastly, hence come the iniquitous disturbance of affairs and the unequal division of "possessions, as a result of which the wealth of nations is heaped up in the hands of a very few private men, who - as We warned you last year, in Our Encyclical Letter Quadragesimo anno - control the trade of the whole world at their will, thereby doing immense harm to the people.
Source: Caritate Christi Compulsi (Vatican.va)