Solidarity is, in the social doctrine of the Church, far more than a feeling of compassion or a generous slogan: it is one of its four permanent principles, alongside the dignity of the human person, the common good and subsidiarity. John Paul II gave it its now-classic definition: not "a feeling of vague compassion or shallow distress at the misfortunes of so many people, both near and far", but "a firm and persevering determination to commit oneself to the common good"[1].
The word itself is recent — it only appeared in the French language at the end of the 17th century, inherited from a term of Roman law (in solidum) — and it first served, in the 19th century, to propose a civil morality meant to replace Christian charity. The Church did not reject it: she purified and adopted it, until it became one of the names of the commandment of love applied to society, under the titles of "friendship", "social charity", and then the "civilization of love"[2].
This principle rests on a fact and leads to a duty. The fact: men and peoples are truly interdependent, bound by a common origin, a common nature and a common destiny. The duty: to transform this endured interdependence into willed responsibility, because, as John Paul II writes, "we are all really responsible for all"[3]. Solidarity is therefore neither the collectivism that dissolves the person into the mass, nor the individualism that ignores the neighbour: it is the active recognition that the good of each passes through the good of all.
This article treats solidarity as a principle of social doctrine: its definition, the history of its name, its foundations, its counterfeits, its inseparable link with subsidiarity, its concrete forms and its properly Christian summit. Related subjects — the common good, subsidiarity, the universal destination of goods, political charity, the option for the poor or peace — are referred to their own articles.
Solidarity, one of the four permanent principles of social doctrine
The social doctrine of the Church is not a political programme but a body of principles drawn from faith and reason, meant to shed light on life in society. The Compendium of the Social Doctrine of the Church, published in 2004 by the Pontifical Council for Justice and Peace, distinguishes four of them, which it calls "permanent" because they hold in every time and place: the dignity of the human person, the common good, subsidiarity and solidarity[4].
Four pillars ordered to the person
These principles are not juxtaposed at random: they form a coherent whole whose centre is the human person, created in the image of God. The dignity of the person is its foundation; the common good is its social end; subsidiarity ensures that intermediate bodies and persons are not crushed from above; solidarity ensures that no one is abandoned below. The Compendium stresses that these principles "must be appreciated in their unity, interrelatedness and articulation" — isolating them from one another distorts them[5].
"These principles, the expression of the whole truth about man known by reason and faith, are born of 'the encounter of the Gospel message and its demands summarized in the supreme commandment of love of God and neighbour and in justice with the problems emanating from the life of society'." — Pontifical Council for Justice and Peace, Compendium of the Social Doctrine of the Church, 2004[6]
What "permanent principle" means
To say that solidarity is a principle and not a mere recommendation has a precise scope. A principle is a foundational truth by which concrete situations are judged: it does not dictate a single technical solution, but it rules out as unjust the social arrangements that contradict it. An economy or a policy that deliberately sacrificed the weak, future generations or poor peoples for the benefit of a few would violate the principle of solidarity, whatever its output[7]. That is why the Church speaks here of a "moral" requirement and not of an optional extra: world peace itself depends on it in part[8].
What is solidarity? The Church's definition
John Paul II's great contribution to social doctrine was to raise solidarity from the rank of feeling to that of virtue and principle. In the encyclical Sollicitudo Rei Socialis (1987), published for the twentieth anniversary of Populorum Progressio, he devotes to the word a decisive analysis that would be taken up word for word by the Catechism and the Compendium[9].
"Neither a feeling of vague compassion"
John Paul II's starting point is a warning: solidarity is constantly threatened with dissolving into emotion. We feel solidarity in the face of a catastrophe, we are moved by distant misery, and then we move on to something else. But that is not it:
"Solidarity is not a feeling of vague compassion or shallow distress at the misfortunes of so many people, both near and far. On the contrary, it is a firm and persevering determination to commit oneself to the common good; that is to say to the good of all and of each individual, because we are all really responsible for all." — Saint John Paul II, Sollicitudo Rei Socialis, no. 38, 30 December 1987[10]
Three words carry the whole weight of this definition. Determination: an act of the will, not a movement of sensibility. Firm and persevering: a stable disposition, one that holds over time and resists weariness. Common good: solidarity is not the sum of particular interests, but the ordering of all to the good of all[11].
A social principle and a moral virtue: the two faces
The Compendium specifies that solidarity has two inseparable faces. It is first a social principle, that is, a criterion for organizing institutions and structures: hence the talk of reforming "structures of sin" through structures of solidarity. It is also a moral virtue, a quality of the person that effectively moves them to draw near to others[12].
"Solidarity must be grasped in its most basic meaning as a demand of the moral order... It is also a true moral virtue, not a 'feeling of vague compassion or shallow distress at the misfortunes of so many people, both near and far'." — Compendium of the Social Doctrine of the Church, no. 193[13]
It is this duality that distinguishes Catholic solidarity from mere philanthropy. Philanthropy relieves effects; solidarity, as virtue and as principle, also attacks causes and commits to the conversion of structures as well as hearts. The Compendium can thus affirm that it "ranks as a basic social virtue"[14].
"We are all responsible for all"
The formula "all responsible for all" condenses the anthropology underlying the whole principle. It does not mean a diffuse and paralysing guilt, but a real and differentiated responsibility: each person answers for the common good according to their place, their means and their power. John Paul II at once draws a consequence for "structures of sin" — those economic and political mechanisms which, once in place, generate injustice independently of individual intentions:
"These attitudes and 'structures of sin' are only conquered... by an attitude which is diametrically opposed: a commitment to the good of one's neighbour, with the readiness, in the Gospel sense, to 'lose oneself' for the sake of the other instead of exploiting him, and to 'serve him' instead of oppressing him for one's own advantage." — Saint John Paul II, Sollicitudo Rei Socialis, no. 38[15]
At the roots of the word: from Roman law to Christian solidarity
The word solidarity has a singular history: born in the vocabulary of jurists, it became in the 19th century the banner of a morality rival to Christianity, before finally being received and transfigured by the Church. Knowing this history avoids two misunderstandings: believing that solidarity is a secular invention foreign to the Gospel, or believing on the contrary that it always belonged to the Christian vocabulary.
In solidum: a debt borne by all
Originally, solidarity is not a feeling but a legal category. In Roman law, the expression in solidum designates the obligation by which several debtors are each bound for the whole: if one pays, the others are released; if one defaults, the creditor may claim everything from the others. The "joint and several obligation" has long belonged to the vocabulary of French law, and the noun solidarity appears there at the end of the 17th century to designate this bond of mutual obligation[16]. The deep intuition is already there: to be in solidarity is to be committed for the whole, not for one's share alone.
Pierre Leroux and the project of replacing charity
The word leaves law for social philosophy with the socialist thinker Pierre Leroux (1797-1871), around the 1840s. Leroux makes solidarity, hitherto legal, the pivot of a morality of humanity meant to do without Christian charity[17]. The project is clear: to substitute for a duty of love founded on God a purely horizontal bond between men, founded on their common belonging to humanity. Solidarity thus becomes, for some, the watchword of a religion of humanity without transcendence.
The solidarism of the Third Republic
This secularization finds its finished political form with the solidarism of Léon Bourgeois (1851-1925), whose work Solidarité (1896) becomes almost the unofficial doctrine of the French Third Republic. Bourgeois develops the idea of a "social debt": each individual is born a debtor toward the society that preceded and formed him, and must discharge this debt through taxation, insurance and cooperation[18]. Solidarism seeks to found a civic morality without recourse to Revelation — which explains the initial wariness of some Catholics toward the term.
The Catholic reappropriation: from "friendship" to "social charity"
The Church did not fight the word: she claimed its truth by reattaching it to its source. The Catechism notes that the principle of solidarity "is also articulated in terms of 'friendship' or 'social charity'"[19]. The term "friendship" comes from Aristotle and Saint Thomas (the civic friendship uniting citizens); that of "social charity" comes from Pius XI in Quadragesimo Anno (1931), who asks that social justice be informed and animated by charity[20]. The Church thus accepts the word solidarity, but by reversing Leroux's project: far from replacing charity, authentic solidarity finds in it its foundation and fulfilment. That is exactly what John Paul II will say in showing that solidarity, a human virtue, "seeks to go beyond itself" to rejoin Christian charity[21].
The foundations of solidarity: why are we bound together?
Solidarity is not a convention that society would be free to adopt or not: it flows from what man is. The Church gives it foundations that are both rational and revealed.
The unity of the human race: a single family
The first foundation is the unity of human nature. All men share the same origin, the same dignity, the same destiny; they form a single human family, as the Council recalls in founding solidarity on the sincere gift of self[22]. The Catechism directly attaches solidarity to this community of origin and to "the equality of rational nature in all men", citing Pius XII's encyclical Summi Pontificatus (1939):
"An error, which is today widely spread, is the forgetfulness of that law of human solidarity and charity, which is dictated and imposed by our common origin and by the equality of rational nature in all men [...] as well as by the redeeming Sacrifice offered by Jesus Christ on the altar of the Cross to His Heavenly Father on behalf of sinful mankind." — Venerable Pius XII, Summi Pontificatus, 1939, quoted in the Catechism no. 1939[23]
"Am I my brother's keeper?"
Scripture poses the question of solidarity from its very first pages. After the murder of Abel, God questions Cain: "Where is your brother?", and Cain answers with the archetypal refusal of all solidarity: "Am I my brother's keeper?"[24]. Genesis thus presents the refusal of fraternal responsibility as the social root of sin. Conversely, the whole Law and the Prophets will call men to "love your neighbour as yourself" (Lv 19:18) and to protect the orphan, the widow and the stranger[25].
The Body of Christ: "if one part suffers..."
The deepest foundation is properly theological. Through baptism, Christians are incorporated into Christ and become members of one another. Saint Paul draws from this the image of the body, which is the charter of Christian solidarity:
"If one part is suffering, all the rest suffer with it; if one part is honoured, all the rest share its joy. Now you together are Christ's body; but each of you is a different part of it." — Saint Paul, First Letter to the Corinthians 12:26-27[26]
What nature begins — the unity of the human race — grace completes: "all of us, though there are so many of us, make up one body in Christ, and as different parts we are all joined to one another"[27]. Christian solidarity is therefore not only a duty toward fellow human beings, but a real communion in one same Body.
Modern interdependence: a fact to be turned into a duty
John Paul II adds a foundation drawn from contemporary experience: globalization has made men and peoples more interdependent than ever. Markets, communications, migrations and ecology bind destinies together. But interdependence is only a fact; it can produce exploitation as well as mutual aid. The role of the principle of solidarity is precisely to transform this fact into a moral value:
"Interdependence must be transformed into solidarity, based upon the principle that the goods of creation are meant for all." — Saint John Paul II, Sollicitudo Rei Socialis, no. 39[28]
It is here that solidarity touches on globalization and the universal destination of goods, treated in their own articles.
Solidarity in Scripture and in the Fathers
Before being a principle formulated by the social Magisterium, solidarity is a gospel practice. Christ did not only teach it: he embodied it and made it the criterion of the Judgment.
The Good Samaritan: who is my neighbour?
To a doctor of the Law seeking to justify himself by asking "and who is my neighbour?", Jesus answers with the parable of the Good Samaritan (Lk 10:25-37). The priest and the Levite "pass by on the other side"; only the despised stranger stops, tends the wounded man and pays for him. The lesson reverses the question: the neighbour is not a category to be delimited in order to know how far my duty extends, but someone whose neighbour I make myself by drawing near. "Go, and do the same yourself"[29]. Benedict XVI sees in it the universalization of the neighbour, which remains concrete: "Anyone who needs me, and whom I can help, is my neighbour"[30].
"What you did to the least"
The discourse on the Last Judgment (Mt 25:31-46) makes concrete solidarity with the poorest the criterion of salvation. The King does not ask for titles or religious merits, but: did I feed, give drink, welcome the stranger, visit the prisoner? And he identifies himself with the little ones:
"I tell you solemnly, in so far as you did this to one of the least of these brothers of mine, you did it to me." — Gospel according to Saint Matthew 25:40[31]
This identification of Christ with the poor is the foundation of the preferential option for the poor, developed in its own article: Christian solidarity is not neutral; it turns first toward the weakest.
The first community of Jerusalem
The Acts of the Apostles describe the community of Jerusalem as the first laboratory of Christian solidarity: "The whole group of believers was united, heart and soul; no one claimed for his own use anything that he had, as everything they owned was held in common"[32]. Saint Paul would later organize a great collection of the Churches of Greece for the poor of Jerusalem, founded on a principle of equality and on the example of Christ: "He was rich, but he became poor for your sake, to make you rich out of his poverty"[33].
The voice of the Fathers
The Fathers of the Church — Saint Basil, Saint Ambrose, Saint John Chrysostom — preached the duty of sharing with an often striking vigour, going so far as to say that keeping one's superfluous goods while the poor go without is stealing from them what is theirs. This tradition directly concerns the universal destination of goods, which is the subject of its own article; let us note here only that it provides the patristic background of the principle of solidarity[34].
Solidarity and subsidiarity: an inseparable pair
The risk, with so powerful a principle, is to make it work alone. A solidarity without restraint can crush freedom and intermediate bodies under a centralizing welfare state; a freedom without solidarity abandons the weak. That is why the Church insists: solidarity and subsidiarity are twin principles that correct each other.
Two principles that correct each other
Subsidiarity requires that decisions be taken at the level closest to people, and that the higher instance intervene only as a subsidy — in support — where the lower one does not suffice. Solidarity, for its part, requires that no one be left alone before what overwhelms them. Benedict XVI formulated their articulation lapidarily in Caritas in Veritate (2009):
"The principle of subsidiarity must be closely linked to the principle of solidarity and vice versa, since the former without the latter gives way to social privatism, while the latter without the former gives way to paternalist social assistance that is demeaning to those in need." — Benedict XVI, Caritas in Veritate, no. 58, 29 June 2009[35]
"Demeaning assistance" versus "social privatism"
This sentence describes the two pathologies that threaten every society. On one side, privatism: each person withdraws into their group, their region, their class, and solidarity stops at the borders of common interest. On the other, assistentialism: an aid that keeps the poor in dependence instead of raising them up, treating them as permanent recipients rather than agents of their own recovery. Good solidarity respects and activates the freedom of the one it helps: it aims to make them capable, not captive. That is why the Compendium specifies that subsidiarity "protects people from abuses by higher social authorities and calls the latter to help individuals and intermediate bodies to develop their functions", without ever supplanting "their initiative, their freedom and their responsibility"[36].
A solidarity ordered to the common good, never to collectivism
Catholic solidarity is not collectivism. Collectivism denies the person and property in the name of the whole; solidarity, on the contrary, presupposes the person, their freedom and even their private property, which it orders to the good of all. This is the great dividing line the Church drew against the ideologies of the 20th century: she condemned atheistic communism and the class struggle, but also the economic liberalism that reduces society to a market. Against both, she proposes solidarity ordered to the common good and tempered by subsidiarity — neither the all-State, nor the individual-king.
The counterfeits of solidarity
Because the word has become popular, it has also become elastic: it is invoked for realities that are only its caricature. Distinguishing authentic solidarity from its counterfeits is a demand of rigour.
The following table contrasts the virtue as defined by the Church with its most common imitations.
| Counterfeit | How it imitates solidarity | Why it is not solidarity |
|---|---|---|
| Feeling without action | Sincere compassion before misfortune | Remains a passing emotion; no "firm and persevering determination" (SRS 38) |
| Class solidarity | Powerfully mobilizes a group | Aims at one camp against another, not the good of all; substitutes struggle for harmony |
| Ideological solidarity | Claims to be "committed" and structural | Selective: in solidarity with only certain poor, according to a partisan grid |
| Assistentialism | Gives and redistributes much | Demeans and keeps people in dependence instead of raising them up (CiV 58) |
| Superfluity philanthropy | Pours money into causes | Touches neither structures nor hearts; relieves the effect without changing causes |
The feeling that does not commit
The first counterfeit is the one John Paul II targets first: emotion without duration. It is sincere, but it changes nothing because it does not turn into stable commitment. True solidarity begins when feeling becomes "determination".
Class solidarity and struggle
Marxism gave the word solidarity a conflictual meaning: solidarity of the proletarians against the bourgeois, in a class struggle posited as the engine of history. The Church recognizes the reality of injustices and the legitimacy of workers' associations — the trade unions have her full support — but she refuses to make struggle the principle. Christian solidarity aims at harmony and the collaboration of classes in view of the common good, not the victory of one camp; that is already what Leo XIII asked from 1891[37].
Ideological and selective solidarity
A solidarity moved only by certain victims, chosen according to a political grid, while remaining blind to others, betrays the universality of the principle. The Church's solidarity is "without borders": it extends to "all and each", including the adversary, the stranger, the unborn child, the condemned. It knows no neighbour "too many".
Assistentialism and dependence
Finally, assistentialism — already encountered with subsidiarity — is the subtlest counterfeit, because it wears the appearance of generosity. But an aid that does not aim to set the other back on their feet is not solidarity: it manages poverty instead of fighting it, and ends up needing poor people to assist.
The concrete forms of solidarity
The Catechism lists the domains in which solidarity is exercised: "solidarity among the poor, between rich and poor, among workers, between employers and employees in a business, solidarity among nations and peoples"[38]. These applications can be grouped into four great circles, each developed by a magisterial text.
Solidarity between persons
The first circle is the most concrete: the neighbour, the family, the local community. It is there that solidarity is verified or belied. Pope Francis insists on this daily dimension of service:
"Solidarity finds concrete expression in service, which can take a variety of forms in an effort to care for others. [...] Service always looks to the brother's face, touches his flesh, senses his closeness [...]" — Pope Francis, Fratelli Tutti, no. 115, 3 October 2020[39]
Solidarity of workers
The second circle is that of work. Leo XIII had defended, from Rerum Novarum (1891), the right of workers to associate; John Paul II, in Laborem Exercens (1981), called for "new movements of solidarity of the workers and with the workers", where exploitation and misery reign[40]. He himself embodied this principle by supporting the Polish union Solidarność — whose very name is "solidarity" — which contributed to the peaceful fall of communism in Eastern Europe.
Solidarity between nations
The third circle is international. It is the major subject of Populorum Progressio (1967), in which Paul VI shows that the development of poor peoples is a duty of justice and solidarity for rich nations, and not a mere alms. His formula has remained famous:
"...if development is the new name for peace, who would not want to work for it with all his might?" — Saint Paul VI, Populorum Progressio, no. 87, 26 March 1967[41]
It is in this sense that the Compendium takes up John Paul II's motto: "Opus solidaritatis pax" — peace is the fruit of solidarity[42] — a point developed in the article on peace.
Solidarity between generations
The fourth circle, more recently brought to light, is intergenerational. In Laudato Si' (2015), Pope Francis recalls that we received the earth as an inheritance and that we owe it to those who come after us: "We are not speaking of an optional attitude, but of an essential question of justice, since the world we have received also belongs to those who will follow us"[43]. This dimension links the principle of solidarity to integral ecology and the safeguarding of creation, the subjects of their own articles.
The development of the principle in the social Magisterium
Solidarity did not appear all at once: it was clarified from encyclical to encyclical, from Leo XIII's first great social text to Francis. The following chronology marks its decisive stages.
- 15 May 1891Rerum Novarum — Leo XIII
The first great social text: against the class struggle, Leo XIII advocates harmony and "friendship" between employers and workers, and defends the right of association.
- 15 May 1931Quadragesimo Anno — Pius XI
Pius XI forges the expression "social charity" and links social justice to charity, laying the groundwork for the future principle of solidarity.
- 20 October 1939Summi Pontificatus — Pius XII
Pius XII speaks of the "law of human solidarity and charity", founded on the unity of the human race and the Redemption — a text quoted by the Catechism.
- 15 May 1961Mater et Magistra — John XXIII
John XXIII develops "socialization" and the growing interdependence of men as a call to an enlarged solidarity.
- 26 March 1967Populorum Progressio — Paul VI
Solidarity becomes international: the duty of rich nations toward the poor; "development is the new name for peace".
- 14 September 1981Laborem Exercens — John Paul II
John Paul II calls for a "solidarity of working people" and with them, echoing the Solidarność movement.
- 30 December 1987Sollicitudo Rei Socialis — John Paul II
The decisive definition: solidarity as a "firm and persevering determination to commit oneself to the common good", virtue and principle.
- 29 June 2009Caritas in Veritate — Benedict XVI
Benedict XVI binds solidarity and subsidiarity indissolubly together, and roots solidarity in "charity in truth".
- 3 October 2020Fratelli Tutti — Francis
Francis re-reads solidarity as "social friendship" and concrete service, starting from the parable of the Good Samaritan.
This continuity illustrates a characteristic of social doctrine: it develops without denying itself, each pope receiving the teaching of his predecessors to apply it to new situations. The solidarity of Leo XIII (harmony of classes), of Paul VI (development of peoples) and of Francis (ecology and migration) is one and the same virtue deployed on successive terrains.
From human virtue to Christian virtue: the summit
The principle of solidarity reaches its full truth when it ceases to be a mere civic morality and becomes charity. This is the movement John Paul II describes at the end of his analysis: solidarity, a human virtue accessible to all, "seeks to go beyond itself".
Solidarity "seeks to go beyond itself"
"In the light of faith, solidarity seeks to go beyond itself, to take on the specifically Christian dimensions of total gratuitousness, forgiveness and reconciliation." — Saint John Paul II, Sollicitudo Rei Socialis, no. 40[44]
Human solidarity gives what is due; Christian charity gives freely, even to the enemy, even to the point of forgiveness. It does not stop at just sharing: it forgives, reconciles, gives itself without calculation. That is why the Compendium can say that "justice alone is not enough" and that it must open itself "to that deeper power which is love"[45].
The neighbour, a "living image of God"
The ultimate motive of Christian solidarity is not social utility, but the supernatural dignity of the other. In faith, the neighbour is no longer only a fellow human being bearing rights:
"One's neighbour is not only a human being with his or her own rights and a fundamental equality with everyone else, but becomes the living image of God the Father, redeemed by the blood of Jesus Christ and placed under the permanent action of the Holy Spirit." — Saint John Paul II, Sollicitudo Rei Socialis, no. 40[46]
The Cross, God's solidarity with man
The ultimate foundation is Christological: by becoming incarnate and dying on the Cross, God made himself one in solidarity with sinful humanity to the point of bearing its burdens. Christian solidarity therefore imitates no abstract ideal, but the very gesture of Christ who "became poor" to enrich us and who bore upon himself the weight of all. As the Compendium sums up:
"Jesus of Nazareth makes the connection between solidarity and charity shine before the eyes of all men, illuminating its entire meaning. In the light of faith, solidarity tends to go beyond itself, to take on the specifically Christian dimensions of total gratuitousness, forgiveness and reconciliation." — Compendium of the Social Doctrine of the Church, no. 196[47]
Solidarity and life in the Divine Will
The spirituality of the Divine Will transmitted to Luisa Piccarreta (1865-1947) offers an interior light on the social principle of solidarity. To live in the Divine Will is to enter into the one single act by which Christ embraces "all and each": the soul that prays and acts in the Fiat never does so for itself alone, but in the name of all creation, restoring to God the glory owed him by all and calling down good upon all men. Solidarity finds here its deepest root — no longer only the responsibility of all toward all, but the communion of all in the one Will of God[48]. It is the highest form of what social doctrine calls, in the order of structures and virtues, solidarity.
To go further
- Subsidiarity — the twin principle of solidarity, which corrects and balances it (Caritas in Veritate 58).
- The common good — the end to which solidarity orders every effort.
- The dignity of the human person — the foundation of the whole principle: we are in solidarity with persons, never with a mass.
- The universal destination of goods — the patristic and doctrinal background of sharing.
- Political charity — the "social" charity that crowns and surpasses solidarity.
- Poverty and the preferential option for the poor — toward whom solidarity turns first.
- Peace — "Opus solidaritatis pax": peace, the fruit of solidarity.
- Globalization — interdependence to be transformed into solidarity.
- Integral ecology and the safeguarding of creation — solidarity between generations.
- Trade unions and social doctrine — the solidarity of workers.
Notes and References
Saint John Paul II, Sollicitudo Rei Socialis, no. 38, 30 December 1987 (official English text, vatican.va). Solidarity is defined there as "a firm and persevering determination to commit oneself to the common good", as opposed to a "feeling of vague compassion or shallow distress".
1Catechism of the Catholic Church, § 1939 (official English text): "The principle of solidarity, also articulated in terms of 'friendship' or 'social charity,' is a direct demand of human and Christian brotherhood."
2Saint John Paul II, Sollicitudo Rei Socialis, no. 38: "because we are all really responsible for all". Latin text: "quia omnes nos pro omnibus revera sumus responsales".
3Pontifical Council for Justice and Peace, Compendium of the Social Doctrine of the Church, Libreria Editrice Vaticana, 2004, nos. 160-163: the four permanent principles of social doctrine are the dignity of the human person, the common good, subsidiarity and solidarity.
4Compendium of the Social Doctrine of the Church, no. 162: the principles of social doctrine "must be appreciated in their unity, interrelatedness and articulation"; none can be isolated without distorting the whole.
5Compendium of the Social Doctrine of the Church, no. 160. On the nature of the permanent principles as the expression of the truth about man known by reason and by faith.
6Compendium of the Social Doctrine of the Church, no. 161: by reason of their permanence in time and universality of meaning, the Church designates these principles as "the primary and fundamental parameter of reference for interpreting and evaluating social phenomena" (official English text, vatican.va).
7Catechism of the Catholic Church, § 1941 (official English text): "International solidarity is a requirement of the moral order; world peace depends in part upon this."
8Saint John Paul II, Sollicitudo Rei Socialis, 30 December 1987, published for the 20th anniversary of Populorum Progressio (1967). The definition of solidarity (nos. 38-40) would be taken up by the Catechism (1992, § 1939-1942) and the Compendium (2004, § 192-196).
9Saint John Paul II, Sollicitudo Rei Socialis, no. 38. Full quotation of the definition of solidarity.
10Saint John Paul II, Centesimus Annus, 1 May 1991, no. 10, takes up and confirms solidarity as a "virtue" and as one of the guiding principles of the social order, in connection with Rerum Novarum.
11Compendium of the Social Doctrine of the Church, no. 193: solidarity has a twofold value, as a "social principle" and as a "moral virtue".
12Compendium of the Social Doctrine of the Church, no. 193, quoting Sollicitudo Rei Socialis no. 38 for the definition of the virtue of solidarity.
13Compendium of the Social Doctrine of the Church, no. 193: solidarity "ranks as a basic social virtue", because it is situated in the domain of justice.
14Saint John Paul II, Sollicitudo Rei Socialis, no. 38, on "structures of sin" and the "diametrically opposed" attitude of service to one's neighbour.
15On the etymology: in solidum designates in Roman law the obligation by which each debtor is bound for the whole. French legal language takes up the notion of "joint and several obligation", and the noun "solidarity" appears there at the end of the 17th century to designate this bond of mutual obligation, before its philosophical and social extension in the 19th century (see the Trésor de la langue française).
16Pierre Leroux (1797-1871) brings the word "solidarity", hitherto reserved to jurists, into social philosophy around the 1840s: solidarity becomes there the purely human bond meant to found a morality independent of Revelation (see the studies in the history of ideas devoted to Leroux and to solidarism).
17Léon Bourgeois (1851-1925), Solidarité, Paris, 1896, theorizes "social debt": the individual is born a debtor toward society and must discharge it. Solidarism becomes the unofficial doctrine of the Third Republic.
18Catechism of the Catholic Church, § 1939 (official English text): the principle of solidarity "is also articulated in terms of 'friendship' or 'social charity'".
19Pius XI, Quadragesimo Anno, 15 May 1931: social justice must be animated by "social charity", an expression taken up by the Catechism (see also the Compendium, no. 193, which attributes this designation to Pius XI).
20Saint John Paul II, Sollicitudo Rei Socialis, no. 40: solidarity, as a virtue, "seeks to go beyond itself" to take on the Christian dimensions of charity (official English text, vatican.va).
21Second Vatican Council, Gaudium et Spes, 7 December 1965, no. 24: man, "the only creature on earth which God willed for itself", cannot "fully find himself except through a sincere gift of self"; the conciliar foundation of solidarity in the unity of the human family.
22Venerable Pius XII, Summi Pontificatus, 20 October 1939, quoted in the Catechism of the Catholic Church, § 1939, on the "law of human solidarity and charity" founded on community of origin and the Redemption.
23Genesis 4:9, Jerusalem Bible: "Where is your brother Abel? [...] Am I my brother's keeper?" The emblematic refusal of fraternal responsibility.
24Leviticus 19:18, Jerusalem Bible: "You must love your neighbour as yourself", taken up by Christ as the second commandment (Mt 22:39).
25First Letter of Saint Paul to the Corinthians 12:26-27, Jerusalem Bible. The image of the body whose members stand together with one another.
26Letter of Saint Paul to the Romans 12:5, Jerusalem Bible: "all of us, though there are so many of us, make up one body in Christ, and as different parts we are all joined to one another".
27Saint John Paul II, Sollicitudo Rei Socialis, no. 39: "Interdependence must be transformed into solidarity", founded on the universal destination of goods.
28Gospel according to Saint Luke 10:25-37, Jerusalem Bible, parable of the Good Samaritan. The conclusion "Go, and do the same yourself" (v. 37) reverses the question "who is my neighbour?".
29Benedict XVI, Deus Caritas Est, 25 December 2005, no. 15: the parable abolishes the limitation of the neighbour to the community of origin — "anyone who needs me, and whom I can help, is my neighbour" (official English text, vatican.va).
30Gospel according to Saint Matthew 25:31-46, Jerusalem Bible. The discourse on the Last Judgment; v. 40: "In so far as you did this to one of the least of these brothers of mine, you did it to me."
31Acts of the Apostles 4:32, Jerusalem Bible: "The whole group of believers was united, heart and soul; [...] everything they owned was held in common"; cf. Acts 2:44-45.
32Second Letter of Saint Paul to the Corinthians 8:9 and 8:13-15, Jerusalem Bible. The collection for the poor of Jerusalem, founded on the example of Christ and on a principle of equality.
33Patristic tradition on the duty of sharing: Saint Basil of Caesarea (homilies on wealth), Saint Ambrose of Milan (De Nabuthae), Saint John Chrysostom (homilies on Lazarus and the rich man). The development and exact quotations belong to the article The universal destination of goods.
34Benedict XVI, Caritas in Veritate, 29 June 2009, no. 58: "The principle of subsidiarity must be closely linked to the principle of solidarity and vice versa, since the former without the latter gives way to social privatism, while the latter without the former gives way to paternalist social assistance that is demeaning to those in need" (official English text, vatican.va).
35Compendium of the Social Doctrine of the Church, nos. 186-187: societies of a higher order must help societies of a lower order without absorbing them; "their initiative, freedom and responsibility must not be supplanted"; the principle "protects people from abuses by higher social authorities and calls the latter to help individuals and intermediate bodies to develop their functions" (official English text, vatican.va).
36Leo XIII, Rerum Novarum, 15 May 1891: against the idea of a class struggle inscribed in nature, the pope shows that the two classes are destined "to dwell in harmony and agreement" and that "concord engenders order and beauty" (official English text, vatican.va).
37Catechism of the Catholic Church, § 1941 (official English text): enumeration of the forms of solidarity (the poor, rich and poor, workers, employers and employees, nations and peoples).
38Pope Francis, Fratelli Tutti, 3 October 2020, no. 115: "Solidarity finds concrete expression in service"; "service always looks to the brother's face, touches his flesh, senses his closeness" (official English text, vatican.va).
39Saint John Paul II, Laborem Exercens, 14 September 1981, no. 8: "there will always have to be new movements of solidarity of the workers and with the workers", wherever "the social degrading of the subject of work, exploitation of the workers and the growing areas of poverty" demand it (official English text, vatican.va).
40Saint Paul VI, Populorum Progressio, 26 March 1967, no. 87: "if development is the new name for peace, who would not want to work for it with all his might?" (official English text, vatican.va).
41Compendium of the Social Doctrine of the Church, no. 203, taking up John Paul II's motto: "Opus solidaritatis pax" — "peace is the fruit of solidarity" (cf. SRS 39).
42Pope Francis, Laudato Si', 24 May 2015, no. 159: "We are not speaking of an optional attitude, but of an essential question of justice, since the world we have received also belongs to those who will follow us" (official English text, vatican.va).
43Saint John Paul II, Sollicitudo Rei Socialis, no. 40: "In the light of faith, solidarity seeks to go beyond itself, to take on the specifically Christian dimensions of total gratuitousness, forgiveness and reconciliation" (official English text, vatican.va).
44Compendium of the Social Doctrine of the Church, no. 203: "Justice alone is not enough [...], it can even deny itself, unless it opens itself to that deeper power which is love."
45Saint John Paul II, Sollicitudo Rei Socialis, no. 40: one's neighbour "becomes the living image of God the Father, redeemed by the blood of Jesus Christ and placed under the permanent action of the Holy Spirit".
46Compendium of the Social Doctrine of the Church, no. 196: "Jesus of Nazareth makes the connection between solidarity and charity shine before the eyes of all men, illuminating its entire meaning", quoting Sollicitudo Rei Socialis no. 40 (official English text, vatican.va).
47A theme of the spirituality of the Divine Will transmitted to Luisa Piccarreta (1865-1947), The Book of Heaven: the soul that lives in the Divine Will acts in the name of all creation, restoring to God the glory owed by all — a universal communion that inwardly founds the duty of solidarity.
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