1. Catholic Social Teaching (CST) serves only one purpose: the flourishing of people in a vibrant society. How do people flourish, when do they develop all their talents, and what makes a society vibrant? What stands in the way of this, and how can it be promoted? These are the questions addressed in CST. Strictly speaking, there is nothing “religious” about it. CST uses reasoning and arguments that are understandable and accessible to non-believers. For example, CST can perfectly take the form of a governance or public administration paradigm that prioritises the vitality and resilience of society. CST is called Catholic because it was developed in a number of papal circular letters – the social encyclicals – and by a number of Catholic philosophers and activists in various countries. However, there is nothing “Catholic” about its themes and arguments.

Social encyclicals
2. Although important steps had been taken earlier, particularly by Thomas Aquinas (13th century) and the School of Salamanca (16th century),^e The European Commission and the European Parliament^e century), the starting point of the KSD is generally laid when the first social encyclical Rerum Novrum (New Times) appeared in 1891. As a social issue, Rerum Novarum addresses the opposition to capital labour and the exploitation of workers and pleads for solidarity and fair pay.

• The social issue addressed in Quadragesimo Anno (1931) is the danger of unbridled state power. The encyclical is a treatise on the proper societal order. It opposes the totalitarian tendencies of the state in (then emerging) fascism and communism and introduces the principle of subsidiarity: the government should not interfere in matters that people and their associations can take care of themselves. Where it does so, its intervention should be aimed at strengthening the capacities of people and their associations. This encyclical also develops the concept of horizontal corporatism, i.e. partnerships between employers and employees in different industries.
• Mater et Magistra (1961) is sometimes referred to as the co-determination encyclical; it argues that employees should have an important say in the management of companies and organisations. This encyclical also explicitly favours the democratic form of government over other forms.
• Pacem in Terris (1963) and Populorum Progressio (1967) address global poverty and development issues and call for international cooperation to bridge the gap between rich and poor countries and for international dialogue to achieve lasting peace.
• Laborem Exercens (1981) is a plea for an economy that puts people first and in which work is seen as a means of personal and social development.
• Sollicitudo Rei Socialis (1987) condemns the greed and selfishness that underlie the sinful structures of capitalism and the unjust distribution of wealth and power, and advocates a holistic development of the human person, encompassing both material and immaterial aspects. Sinful structures of capitalism and the unjust distribution of wealth and power, and advocates a holistic development of man, covering both material and intangible aspects.
• Centesimus Annus (1991) reflects on the fall of the Berlin Wall and warns against unbridled capitalism that will be detrimental to human dignity, the environment and future generations, ending with a plea for an ‘economy of solidarity’.
• Deus Caritas Est (2006) explores the meaning of love in the Christian faith. It distinguishes between two forms of love: eros (desiring love) and agape (giving love). Both forms are inherently good, but from a Christian perspective, agape is the highest form.
• Caritas in Veritate (2009) goes into the relationship between charity and truth, stressing that the two should always be approached in conjunction. Social progress cannot be separated from ethical and spiritual considerations.
• Laudato Si' (2015) is a general cultural criticism of modernity and its technocratic paradigm, characterized by complexity. It culminates in an urgent call to begin the - necessarily long - process of regeneration and integral-ecological coexistence.
• Fratelli Tutti (2020) is the complement of Laudato Si. It is a call to universal fraternity and social friendship, and stresses the importance of dialogue and meeting among people with different backgrounds and beliefs as a way to promote mutual understanding and empathy, condition for the flourishing of people and for a vital society.

Socio-economic issues
3. From the outset, therefore, the KSD has a wide focus on socio-economic issues, economic planning, the dignity of work and the organisation of enterprises. In several countries this has been translated into practical terms in the creation of workers' organisations for their representation and their fight for social justice. In the Netherlands, for example, Alphons Ariëns and Henri Poels, in Belgium Adolf Daens and Jozef Cardijn, in Germany Oskar von Nell-Breuning and in the USA John Ryan and Dorothy Day. In the years after World War II, the period of reconstruction, the struggle for social justice has moved to the political arena. In the Netherlands and Belgium, Christian and Social Democrats found each other (the Roman-red coalitions, of 1945-58) in building the welfare state, based on solidarity and social security.

Social organisation
4. Since then, the working and living conditions of workers and their families have improved considerably. At the same time, it can be noted that important dimensions of the KSD have been lost in this process of detection, unintentionally; That the KSD is here united and flattened. This applies first of all to the principle of subsidiarity, which was declared in Quadragesimo Anno (1931) to be the "all-weightest principle" of the KSD on social order. In the words of the philosopher Herman Dooyeweerd (n.a. Protestant) this principle was "to set up a dam against totalitarian state absolutism, not by imposing the order from above, but from below, so that the government should leave the planning task to the few and to the lower communities as much as possible." At that time, Dooyeweerd could hope that the Catholics who adhere to this principle of subsidiarity, "in practical politics would rather side with Calvinism, which choose sovereignty as a guideline in its own circle, than on the side of modern rulers. In reality, virtually all Protestant and Catholic politicians cooperated wholeheartedly in the enormous expansion, after World War II, of the state presence in social life. Protestant political leader Gert Schutte subsequently noted: "After 1950, the principle of sovereignty in its own circle was slowly abandoned, because of its conservative effects on the pursuit of public order and building up the welfare society.

4. Since then, the working and living conditions of workers and their families have improved considerably. At the same time, it can be noted that important dimensions of the KSD have been lost in this process of detection, unintentionally; That the KSD is here united and flattened. This applies first of all to the principle of subsidiarity, which was declared in Quadragesimo Anno (1931) to be the "all-weightest principle" of the KSD on social order. In the words of the philosopher Herman Dooyeweerd (n.a. Protestant) this principle was "to set up a dam against totalitarian state absolutism, not by imposing the order from above, but from below, so that the government should leave the planning task to the few and to the lower communities as much as possible." At that time, Dooyeweerd could hope that the Catholics who adhere to this principle of subsidiarity, "in practical politics would rather side with Calvinism, which choose sovereignty as a guideline in its own circle, than on the side of modern rulers. In reality, virtually all Protestant and Catholic politicians cooperated wholeheartedly in the enormous expansion, after World War II, of the state presence in social life. Protestant political leader Gert Schutte subsequently noted: "After 1950, the principle of sovereignty in its own circle was slowly abandoned, because of its conservative effects on the pursuit of public order and building up the welfare society.
Social vs Social 5. The emancipation of the workers over decades gained so much weight that the adjective Social 5. The emancipation of the workers over decades gained so much weight that the adjective in Catholic (or in the Social

Learn from the Church) was almost identified with the meaning it has in terms of social justice and social security. Socially, it refers to the protection of the poor and the weak and equal opportunities for all. 5. The emancipation of the workers over decades gained so much weight that the adjective Social 5. The emancipation of the workers over decades gained so much weight that the adjective But this meant that the KSD was gradually limited to that. That can't be the intention. After all, the KSD is broader: - the human person and society.

Thinking stands for: the whole society concerning.

KSD is about thriving people in a vital society. Of course, exploitation and injustice stand in the way here and it is at issue for the KSD to decide on this. At the same time, the principle of subsidiarity must be followed - questions must be raised about the development of the welfare state and the public presence in society. In France, the great Catholic-social thinker Emmanuel Mounier warned in 1949: "The central starting point of personalism is the existence of free and creative persons. Nothing stands at such a strain as the pursuit, today being carried so widely, to a system of thought and action, which spits out solutions and instructions like an automaton, which paralyzes the search process and protects man from unrest, testing and risk." By removing matter and motives for people to work themselves and with others, the welfare state can get in the way of the flourishing of individuals, of their connections and of society.

The KSD must therefore be rethinked and reclaimed to politicians and academics. That can begin with a consideration of the four pillars: human dignity, Bonum commune, subsidiarity and solidarity.

The four "pillars"
7.About the concept of human dignity. The standard story is that every human being has an intrinsic dignity that must be protected.

Of course there is nothing to argue with. But in the real KSD the concept gets a completely different dimension. So Mounier says: "Tout homme, sans exception, a le droit et le devoir de développer sa personalité”. Every human being, without exception, has the right and duty to develop his or her personality. Dignity is not a given, but something that awaits realization. For Mounier, it is about people developing their talents and thus realising their dignity as a person; human-be. And becoming human, humanizing, only that man himself, no one else can. And that is his right but also duty, responsibility. That responsibility should not be taken over by others. That precisely threatens to happen if we make him or her an object of our protection in the personal relationship as well as because of the welfare state. No, it says KSD, all wrong.

What we have to do, Mounier said, is to remove the obstacles to human development: "The first duty we owe to everyone else is to fight the psychological or social conditions that make it impossible for them to fully develop their talents."

Subsidiarity
8. In doing so, we have successfully introduced another core concept in the KSD, namely subsidiarity. This is important in order to put subsidiarity into the right context, because, like dignity, this concept is trivialised in many ways.

Like solidarity, subsidiarity is a relational concept, it is about the nature and commitment of relationships. But where solidarity calls for help and assistance, subsidiarity stands for a relationship logic that fully recognises the dignity and own responsibility of the other and that explores how best to contribute to its development - which in any case means that the other is not deprived of substance and motive to grow himself but is helped to realize his or her dignity.

This "all-weight principle" (QA) of the KSD does not only apply to the relationship between two persons. No, subsidiarity is a comprehensive political-social, administrative, organisational and professional paradigm. The core of it is that one: the government, the director, the manager, the professional; one man should not take away the other's motives to take initiative, to engage with other people, to take responsibility freely and to develop his/her creative, social and moral talents. On the contrary, everyone must leave room for others, remove obstacles, and promote and support their own initiative and responsibility. Because: everything that has to be done, the tasks that are to be accomplished, the goals that are to be realized, the problems that demand a solution . . they are the matter and they are as many potential motives for people to meet and to take responsibility together in freedom and they are as many vehicles for the development of their creative, social and moral talents and the vitalization of their connections.

Subsidiarity vs. Sovereignty in its own circle
9. Sovereignty in its own circle is a principle in Christian (calvinistic) social thinking that states that every circle of life, such as the family, the church, education, the economy - has its own independent authority and is not under that of another circle of life. We have already seen (point 4) that this principle has in common with the principle of subsidiarity that it is opposed to state absolutism and to a broader . Therefore the two are sometimes called each other's equivalent. However, this is only partially correct and, in a way, they are even opposed to each other. In essence, sovereignty in its own circle stands for separation: This is mine and that's yours and we have nothing to do with each other. Subsidiarity is precisely a relationship, a inter-relationship, a dynamic division of labour within a shared responsibility with a view to optimising humanisation and vitalization effects.

Some quotes from social encyclicals
10. Blooming people in vital contexts, a strong society - that's what it all started in the KSD. Everything that could stand in the way of this process is therefore rejected in encyclicals in the strictest terms. Some illustrative quotes from different encyclicals:

"Even if it is a serious mistake to take away from them what individuals can achieve through their own initiative and industry in order to give it to the community, it is also an injustice and, at the same time, a serious evil and impairment of the right order to give a greater and higher connection to what the lower and subordinate organization can do." (Quadragesimo Anno 79-80)

About the importance of encounters for human development: "Man as a spiritual creature realizes himself through interpersonal relations. The more he experiences these relationships in an authentic way, the more mature his own personal identity. Not by seclusion does man come to his right, but by placing himself in relation to others and with God. The meaning of such relationships is therefore fundamental." (Caritas in Veritate 53)

About the relationship between meeting, personal development and vital society: "It is important to create meeting processes, [...] to encourage people to work together, side by side, in pursuing goals that benefit everyone. A wide range of practical proposals and various experiences can help to achieve common objectives and serve the general interest." (Fratelli Tutti, 2020, 217-228)

Laudato Si and Fratelli Tutti
11. With the encyclicals Laudato Si and Fratelli Tutti, Pope Francis gave a tremendous boost to the KSD. Where earlier social encyclicals have focused on specific social issues, the exploitation of workers, the indignity of work, the family in the throes, the unequal development and unfair international relations, the danger of totalitarian state, of statistical and bureaucracy, Laudato Si a comprehensive cultural criticism of modernity, i.e. the Western world over the last two hundred years. Modernity first brought us enormous growth and prosperity, but the same technocratic mindset that was instrumental for that now turns against man and the whole planet. Recovery will require long regeneration processes. We have to deal with our common house differently and with each other. Fratelli Tutti fills in the latter, with a reflection on brotherhood and a call to meet.