88 Attention must be given also to another matter that is closely connected with the foregoing. Just as the unity of human society cannot be founded on an opposition of classes, so also the right ordering of economic life cannot be left to a free competition of forces. For from this source, as from a poisoned spring, have originated and spread all the errors of individualist economic teaching. Destroying through forgetfulness or ignorance the social and moral character of economic life, it held that economic life must be considered and treated as altogether free from and independent of public authority, because in the market, i.e., in the free struggle of competitors, it would have a principle of self direction which governs it much more perfectly than would the intervention of any created intellect. But free competition, while justified and certainly useful provided it is kept within certain limits, clearly cannot direct economic life - a truth which the outcome of the application in practice of the tenets of this evil individualistic spirit has more than sufficiently demonstrated. Therefore, it is most necessary that economic life be again subjected to and governed by a true and effective directing principle. This function is one that the economic dictatorship which has recently displaced free competition can still less perform, since it is a headstrong power and a violent energy that, to benefit people, needs to be strongly curbed and wisely ruled. But it cannot curb and rule itself. Loftier and nobler principles - social justice and social charity - must, therefore, be sought whereby this dictatorship may be governed firmly and fully. Hence, the institutions themselves of peoples and, particularly those of all social life, ought to be penetrated with this justice, and it is most necessary that it be truly effective, that is, establish a juridical and social order which will, as it were, give form and shape to all economic life. Social charity, moreover, ought to be as the soul of this order, an order which public authority ought to be ever ready effectively to protect and defend. It will be able to do this the more easily as it rids itself of those burdens which, as We have stated above, are not properly its own.
Source: Quadragesimo Anno (Vatican.va)