a. Meaning and value
192. Solidarity highlights in a particular way the intrinsic social nature of the human person, the equality of all in dignity and rights and the common path of individuals and peoples towards an ever more committed unity. Never before has there been such a widespread awareness of the bond of interdependence between individuals and peoples, which is found at every level[413]. The very rapid expansion in ways and means of communication “in real time”, such as those offered by information technology, the extraordinary advances in computer technology, the increased volume of commerce and information exchange all bear witness to the fact that, for the first time since the beginning of human history, it is now possible — at least technically — to establish relationships between people who are separated by great distances and are unknown to each other.
In the presence of the phenomenon of interdependence and its constant expansion, however, there persist in every part of the world stark inequalities between developed and developing countries, inequalities stoked also by various forms of exploitation, oppression and corruption that have a negative influence on the internal and international life of many States. The acceleration of interdependence between persons and peoples needs to be accompanied by equally intense efforts on the ethical-social plane, in order to avoid the dangerous consequences of perpetrating injustice on a global scale. This would have very negative repercussions even in the very countries that are presently more advantaged[414].
b. Solidarity as a social principle and a moral virtue
193. The new relationships of interdependence between individuals and peoples, which are de facto forms of solidarity, have to be transformed into relationships tending towards genuine ethical-social solidarity. This is a moral requirement inherent within all human relationships. Solidarity is seen therefore under two complementary aspects: that of a social principle[ 415] and that of a moral virtue[416].
Solidarity must be seen above all in its value as a moral virtue that determines the order of institutions. On the basis of this principle the “structures of sin”[417] that dominate relationships between individuals and peoples must be overcome. They must be purified and transformed into structures of solidarity through the creation or appropriate modification of laws, market regulations, and juridical systems.
Solidarity is also an authentic moral virtue, 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”[418]. Solidarity rises to the rank of fundamental social virtue since it places itself in the sphere of justice. It is a virtue directed par excellence to the common good, and is found in “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 (cf. Mt 10:40-42, 20:25; Mk 10:42-45; Lk 22:25-27)”[419].
c. Solidarity and the common growth of mankind
194. The message of the Church's social doctrine regarding solidarity clearly shows that there exists an intimate bond between solidarity and the common good, between solidarity and the universal destination of goods, between solidarity and equality among men and peoples, between solidarity and peace in the world[420]. The term “solidarity”, widely used by the Magisterium[421], expresses in summary fashion the need to recognize in the composite ties that unite men and social groups among themselves, the space given to human freedom for common growth in which all share and in which they participate. The commitment to this goal is translated into the positive contribution of seeing that nothing is lacking in the common cause and also of seeking points of possible agreement where attitudes of separation and fragmentation prevail. It translates into the willingness to give oneself for the good of one's neighbour, beyond any individual or particular interest[422].
195. The principle of solidarity requires that men and women of our day cultivate a greater awareness that they are debtors of the society of which they have become part. They are debtors because of those conditions that make human existence liveable, and because of the indivisible and indispensable legacy constituted by culture, scientific and technical knowledge, material and immaterial goods and by all that the human condition has produced. A similar debt must be recognized in the various forms of social interaction, so that humanity's journey will not be interrupted but remain open to present and future generations, all of them called together to share the same gift in solidarity.
d. Solidarity in the life and message of Jesus Christ
196. The unsurpassed apex of the perspective indicated here is the life of Jesus of Nazareth, the New Man, who is one with humanity even to the point of “death on a cross” (Phil 2:8). In him it is always possible to recognize the living sign of that measureless and transcendent love of God-with-us, who takes on the infirmities of his people, walks with them, saves them and makes them one[423]. In him and thanks to him, life in society too, despite all its contradictions and ambiguities, can be rediscovered as a place of life and hope, in that it is a sign of grace that is continuously offered to all and because it is an invitation to ever higher and more involved forms of sharing.
Jesus of Nazareth makes the connection between solidarity and charity shine brightly before all, illuminating the entire meaning of this connection[424]: “In the light of faith, solidarity seeks to go beyond itself, to take on the specifically Christian dimensions of total gratuity, forgiveness and reconciliation. One's neighbour is then 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. One's neighbour must therefore be loved, even if an enemy, with the same love with which the Lord loves him or her; and for that person's sake one must be ready for sacrifice, even the ultimate one: to lay down one's life for the brethren (cf. 1 Jn 3:16)”[425].
a. The relationship between principles and values
197. Besides the principles that must guide the building of a society worthy of man, the Church's social doctrine also indicates fundamental values. The relationship between principles and values is undoubtedly one of reciprocity, in that social values are an expression of appreciation to be attributed to those specific aspects of moral good that these principles foster, serving as points of reference for the proper structuring and ordered leading of life in society. These values require, therefore, both the practice of the fundamental principles of social life and the personal exercise of virtue, hence of those moral attitudes that correspond to these very values[426].
All social values are inherent in the dignity of the human person, whose authentic development they foster. Essentially, these values are: truth, freedom, justice, love[427]. Putting them into practice is the sure and necessary way of obtaining personal perfection and a more human social existence. They constitute the indispensable point of reference for public authorities, called to carry out “substantial reforms of economic, political, cultural and technological structures and the necessary changes in institutions”[428]. Respect for the legitimate autonomy of earthly realities prompts the Church not to claim specific competence of a technical or temporal order[429], but it does not prevent her from intervening to show how, in the different choices made by men and women, these values are either affirmed or denied[430].
b. Truth
198. Men and women have the specific duty to move always towards the truth, to respect it and bear responsible witness to it[431]. Living in the truth has special significance in social relationships. In fact, when the coexistence of human beings within a community is founded on truth, it is ordered and fruitful, and it corresponds to their dignity as persons[432]. The more people and social groups strive to resolve social problems according to the truth, the more they distance themselves from abuses and act in accordance with the objective demands of morality.
Modern times call for an intensive educational effort [433] and a corresponding commitment on the part of all so that the quest for truth cannot be ascribed to the sum of different opinions, nor to one or another of these opinions — will be encouraged in every sector and will prevail over every attempt to relativize its demands or to offend it[434]. This is an issue that involves the world of public communications and that of the economy in a particular way. In these areas, the unscrupulous use of money raises ever more pressing questions, which necessarily call for greater transparency and honesty in personal and social activity.
c. Freedom
199. Freedom is the highest sign in man of his being made in the divine image and, consequently, is a sign of the sublime dignity of every human person[435]. “Freedom is exercised in relationships between human beings. Every human person, created in the image of God, has the natural right to be recognized as a free and responsible being. All owe to each other this duty of respect. The right to the exercise of freedom, especially in moral and religious matters, is an inalienable requirement of the dignity of the human person”[436]. The meaning of freedom must not be restricted, considering it from a purely individualistic perspective and reducing it to the arbitrary and uncontrolled exercise of one's own personal autonomy: “Far from being achieved in total self-sufficiency and the absence of relationships, freedom only truly exists where reciprocal bonds, governed by truth and justice, link people to one another”[437]. The understanding of freedom becomes deeper and broader when it is defended, even at the social level, in all of its various dimensions.
200. The value of freedom, as an expression of the singularity of each human person, is respected when every member of society is permitted to fulfil his personal vocation; to seek the truth and profess his religious, cultural and political ideas; to express his opinions; to choose his state of life and, as far as possible, his line of work; to pursue initiatives of an economic, social or political nature. This must take place within a “strong juridical framework”[438], within the limits imposed by the common good and public order, and, in every case, in a manner characterized by responsibility.
On the other hand, freedom must also be expressed as the capacity to refuse what is morally negative, in whatever guise it may be presented[439], as the capacity to distance oneself effectively from everything that could hinder personal, family or social growth. The fullness of freedom consists in the capacity to be in possession of oneself in view of the genuine good, within the context of the universal common good[440].
d. Justice
201. Justice is a value that accompanies the exercise of the corresponding cardinal moral virtue[441]. According to its most classic formulation, it “consists in the constant and firm will to give their due to God and neighbour”[442]. From a subjective point of view, justice is translated into behaviour that is based on the will to recognize the other as a person, while, from an objective point of view, it constitutes the decisive criteria of morality in the intersubjective and social sphere[443].
The Church's social Magisterium constantly calls for the most classical forms of justice to be respected: commutative, distributive and legal justice[444]. Ever greater importance has been given to social justice[445], which represents a real development in general justice, the justice that regulates social relationships according to the criterion of observance of the law. Social justice, a requirement related to the social question which today is worldwide in scope, concerns the social, political and economic aspects and, above all, the structural dimension of problems and their respective solutions[446].
202. Justice is particularly important in the present-day context, where the individual value of the person, his dignity and his rights — despite proclaimed intentions — are seriously threatened by the widespread tendency to make exclusive use of criteria of utility and ownership. Justice too, on the basis of these criteria, is considered in a reductionist manner, whereas it acquires a fuller and more authentic meaning in Christian anthropology. Justice, in fact, is not merely a simple human convention, because what is “just” is not first determined by the law but by the profound identity of the human being[447].
203. The full truth about man makes it possible to move beyond a contractualistic vision of justice, which is a reductionist vision, and to open up also for justice the new horizon of solidarity and love. “By itself, justice is not enough. Indeed, it can even betray itself, unless it is open to that deeper power which is love”[448]. In fact, the Church's social doctrine places alongside the value of justice that of solidarity, in that it is the privileged way of peace. If peace is the fruit of justice, “today one could say, with the same exactness and the same power of biblical inspiration (cf. Is 32:17; Jas 3:18): Opus solidaritatis pax, peace as the fruit of solidarity”[449]. The goal of peace, in fact, “will certainly be achieved through the putting into effect of social and international justice, but also through the practice of the virtues which favour togetherness, and which teach us to live in unity, so as to build in unity, by giving and receiving, a new society and a better world”[450].

thanks to vatican.va