Pope Pius XI
Quadragesimo Anno §17
Quadragesimo Anno: On Reconstruction of the Social Order
17 In the first place Leo himself clearly stated what ought to be expected from the Church: "Manifestly it is the Church which draws from the Gospel the teachings through which the struggle can be composed entirely, or, after its bitterness is removed, can certainly become more tempered. It is the Church, again, that strives not only to instruct the mind, but to regulate by her precepts the life and morals of individuals, and that ameliorates the condition of the workers through her numerous and beneficent institutions "
Source: Quadragesimo Anno (Vatican.va)