The Magisterium recognizes the fundamental role played by labour unions, whose existence is connected with the right to form associations or unions to defend the vital interests of workers employed in the various professions. Unions “grew up from the struggle of the workers — workers in general but especially the industrial workers — to protect their just rights vis-à-vis the entrepreneurs and the owners of the means of production”.667John Paul II, Encyclical Letter Laborem Exercens, 20: AAS 73 (1981), 629. Such organizations, while pursuing their specific purpose with regard to the common good, are a positive influence for social order and solidarity, and are therefore an indispensable element of social life. The recognition of workers' rights has always been a difficult problem to resolve because this recognition takes place within complex historical and institutional processes, and still today it remains incomplete. This makes the practice of authentic solidarity among workers more fitting and necessary than ever.
The Church's social doctrine teaches that relations within the world of work must be marked by cooperation: hatred and attempts to eliminate the other are completely unacceptable. This is also the case because in every social system both “labour” and “capital” represent indispensable components of the process of production. In light of this understanding, the Church's social doctrine “does not hold that unions are no more than a reflection of the ‘class' structure of society and that they are a mouthpiece for a class struggle which inevitably governs social life”.668John Paul II, Encyclical Letter Laborem Exercens, 20: AAS 73 (1981), 630. Properly speaking, unions are promoters of the struggle for social justice, for the rights of workers in their particular professions: “This struggle should be seen as a normal endeavour ‘for' the just good ... not a struggle ‘against' others”.669John Paul II, Encyclical Letter Laborem Exercens, 20: AAS 73 (1981), 630. Being first of all instruments of solidarity and justice, unions may not misuse the tools of contention; because of what they are called to do, they must overcome the temptation of believing that all workers should be union-members, they must be capable of self-regulation and be able to evaluate the consequences that their decisions will have on the common good.670Cf. Catechism of the Catholic Church, 2430.
Beyond their function of defending and vindicating, unions have the duty of acting as representatives working for “the proper arrangement of economic life” and of educating the social consciences of workers so that they will feel that they have an active role, according to their proper capacities and aptitudes, in the whole task of economic and social development and in the attainment of the universal common good.671Cf. Second Vatican Ecumenical Council, Pastoral Constitution Gaudium et Spes, 68: AAS 58 (1966), 1090. Unions and other forms of labour associations are to work in cooperation with other social entities and are to take an interest in the management of public matters. Union organizations have the duty to exercise influence in the political arena, making it duly sensitive to labour problems and helping it to work so that workers' rights are respected. Unions do not, however, have the character of “political parties” struggling for power, and they should not be forced to submit to the decisions of political parties nor be too closely linked to them. “In such a situation they easily lose contact with their specific role, which is to secure the just rights of workers within the framework of the common good of the whole of society; instead they become an instrument used for other purposes”.672John Paul II, Encyclical Letter Laborem Exercens, 20: AAS 73 (1981), 631.