Despite the fact that the Catholic Church has unequivocally condemned socialism, the idea that the State is the real owner of everything and can tax and redistribute for social purposes at will has pervaded Catholic social teaching since at least the mid-1880s. This was when the agrarian socialist Henry George and Archbishop Michael A. Corrigan of New York went at it hammer and tongs.
There is evidence suggesting that Rerum Novarum was, in fact, issued in part to refute the claims of George, which the non-Catholic George insisted were authentic Catholic teaching. This was in spite of the fact that George was carefully instructed regarding the truth about Catholic social teaching and why his theories — particularly the idea that the State has the right to tax for social purposes, taking all rents and profits from land ownership as a 100% “single tax” — are in error. As Leo XIII explained,
“The right to possess private property is derived from nature, not from man; and the State has the right to control its use in the interests of the public good alone, but by no means to absorb it altogether. The State would therefore be unjust and cruel if under the name of taxation it were to deprive the private owner of more than is fair.” (Rerum Novarum, § 47.)
And what is “fair”? Enough to offset the legitimate cost of government — but no more. (Cf. John Locke, Second Treatise on Government, § 140.) The State’s job is to care for the common good, not every individual’s personal good. As Leo XIII explained,
“[M]an not only should possess the fruits of the earth, but also the very soil, inasmuch as from the produce of the earth he has to lay by provision for the future. Man's needs do not die out, but forever recur; although satisfied today, they demand fresh supplies for tomorrow. Nature accordingly must have given to man a source that is stable and remaining always with him, from which he might look to draw continual supplies. And this stable condition of things he finds solely in the earth and its fruits. There is no need to bring in the State. Man precedes the State, and possesses, prior to the formation of any State, the right of providing for the substance of his body.” (Ibid., § 7.)
True, we are required to care for the poor and give them alms (charity) when they are in need. This, however, is not the job of the State, except in extreme circumstances as a temporary expedient. As the pope explained,
|Hobbes's "Mortall God": the State.
“[I]f the question be asked: How must one's possessions be used? — the Church replies without hesitation in the words of the same holy Doctor: ‘Man should not consider his material possessions as his own, but as common to all, so as to share them without hesitation when others are in need. Whence the Apostle with, ‘Command the rich of this world . . . to offer with no stint, to apportion largely.’ True, no one is commanded to distribute to others that which is required for his own needs and those of his household; nor even to give away what is reasonably required to keep up becomingly his condition in life, ‘for no one ought to live other than becomingly.’ But, when what necessity demands has been supplied, and one's standing fairly taken thought for, it becomes a duty to give to the indigent out of what remains over. ‘Of that which remaineth, give alms.’ It is a duty, not of justice (save in extreme cases), but of Christian charity — a duty not enforced by human law.” (Ibid., § 22.)
Obviously, then, taxation “for social purposes” must be considered contrary to Catholic social teaching, as well as to the natural law on which Catholic social teaching is based.