Pope John XXIII
Mater et Magistra §208
Mater et Magistra: On Christianity and Social Progress
208 But the moral order has no existence except in God; cut off from God it must necessarily disintegrate. Moreover, man is not just a material organism. He consists also of spirit; he is endowed with reason and freedom. He demands, therefore, a moral and religious order; and it is this order—and not considerations of a purely extraneous, material order—which has the greatest validity in the solution of problems relating to his life as an individual and as a member of society, and problems concerning individual states and their inter-relations.
Source: Mater et Magistra (Vatican.va)