“The seventh commandment forbids unjustly taking or keeping the goods of one's neighbor and wronging him in any way with respect to his goods. It commands justice and charity in the care of earthly goods and the fruits of men's labor. For the sake of the common good, it requires respect for the universal destination of goods and respect for the right to private property. Christian life strives to order this world's goods to God and to fraternal charity" (Catechism 2401).
1. The universal destiny and private ownership of goods
“In the beginning God entrusted the earth and its resources to the common stewardship of mankind to take care of them, master them by labor, and enjoy their fruits (cf. Gen 1:26-29). The goods of creation are destined for the whole human race" (Catechism 2402).
However, “the appropriation of property is legitimate for guaranteeing the freedom and dignity of persons and for helping each of them to meet his basic needs and the needs of those in his charge" ( Ibid. ).
“The right to private property , acquired or received in a just way, does not do away with the original gift of the earth to the whole of mankind. The universal destination of goods remains primordial,  even if the promotion of the common good requires respect for the right to private property and its exercise" (Catechism 2403). Respecting the right to private property is important for the orderly development of social life.
“'In his use of things man should regard the external goods he legitimately owns not merely as exclusive to himself but common to others also, in the sense that they can benefit others as well as himself' (Vatican Council II, Const. Gaudium et spes , 69, 1). The ownership of any property makes its holder a steward of Providence, with the task of making it fruitful and communicating its benefits to others, first of all his family" (Catechism 2404).
Marxist socialism, and particularly communism, in seeking among other things the complete subordination of the individual to society, denies the right of the person to private ownership of the goods of production (those used to produce other goods, such as land, certain industries, etc.), affirming that only the state can possess these goods, as the condition for instituting a “classless"society. 
“The Church has rejected the totalitarian and atheistic ideologies associated in modem times with 'communism' or 'socialism.' She has likewise refused to accept, in the practice of 'capitalism,' individualism and the absolute primacy of the law of the marketplace over human labor" (Catechism 2425). 
2. Use of goods: temperance, justice and solidarity
“In economic matters, respect for human dignity requires the practice of the virtue of temperance , so as to moderate attachment to this world's goods; the practice of the virtue of justice , to preserve our neighbor's rights and render him what is his due; and the practice of solidarity " (Catechism 2407).
The virtue of poverty, which is part of temperance, is not a matter of “not possessing" things but of not being attached to material goods, of being happy with what suffices for a sober and moderate life,  as well as administrating goods as a service to others. Our Lord gave us an example of poverty and detachment right from his coming into this world to his death on the Cross (cf. 2 Cor 8, 9). Likewise he warned of the harm attachment to riches can cause: It will be hard for a rich man to enter the kingdom of heaven (Mt 19:23).
As a moral virtue, justice consists of the habit whereby with a firm and constant will one gives to everyone their due. Justice between individual persons is called commutative justice (for example paying a debt); distributive justice “regulates what the community owes its citizens in proportion to their contributions and needs" (Catechism 2411);  and legal justice is that of the citizen with regard to the community (for example, paying just taxes).
The virtue of solidarity is “the firm and constant decision to insist on fostering the common good, that is, the good of each and every person, because we are all truly responsible for everyone."  Solidarity is the “sharing of spiritual goods even more than material ones" ( Catechism 1948).
3. Respecting the goods of others
The seventh commandment forbids taking or keeping unjustly what is our neighbor's, or causing him unjust harm in his material goods. Theft or stealing is committed when another's goods are taken secretly. Robbery is the violent seizing of another's goods. Fraud is theft by means of deceiving one's neighbor with traps, false documents, etc., or withholding a just salary. Usury consists in claiming greater interest than is lawful for the amount loaned (generally, taking advantage of a neighbor in financial straits).
“The following are also morally illicit: speculation in which one contrives to manipulate the price of goods artificially in order to gain an advantage to the detriment of others; corruption in which one influences the judgment of those who must make decisions according to law; appropriation and use for private purposes of the common goods of an enterprise; work poorly done; tax evasion; forgery of checks and invoices; excessive expenses and waste. Willfully damaging private or public property is contrary to the moral law and requires reparation" (Catechism 2409).
“Contracts are subject to commutative justice which regulates exchanges between persons in accordance with a strict respect for their rights. Commutative justice obliges strictly; it requires safeguarding property rights, paying debts, and fulfilling obligations freely contracted" (Catechism 2411). “Contracts [must be] strictly observed to the extent that the commitments made in them are morally just" (Catechism 2410).
There is an obligation to make reparation : anyone committing an injustice must make reparation for the harm caused insofar as is possible. The restitution of stolen goods —or at least the desire and intention to do so—is necessary to receive sacramental absolution. The duty of restitution is an urgent obligation: guilty delay increases the creditor's harm and the debtor's guilt. The physical or moral impossibility, as long as it lasts, excuses from the duty to reimburse. The duty can be eliminated if, for example, the debt is pardoned by the creditor. 
4. The social doctrine of the Church
“When [the Church] fulfills her mission of proclaiming the Gospel, she bears witness to man, in the name of Christ, to his dignity and his vocation to the communion of persons. She teaches him the demands of justice and peace in conformity with divine wisdom" (Catechism 2419). The collection of these teachings on the principles that should guide social life is called social doctrine and is part of Catholic moral doctrine. 
Among the fundamental teachings of the social doctrine of the Church are: 1) the transcendent dignity of the human person and the inviolability of his or her rights; 2) recognizing as the basic cell of society the family founded on true indissoluble matrimony, and the need to protect it and foster it through sound laws on matrimony, education and public morality; 3) teachings concerning the common good and the role of the state.
The mission of the hierarchy of the Church differs from the mission of the political authority. The aim of the Church is supernatural and its mission is to lead men to salvation. This is why, when the Magisterium refers to temporal aspects of the common good, it does so insofar as they should be ordered to the supreme Good, our ultimate destiny. The Church gives a moral judgment on economic and social questions “when required for the fundamental rights of the person or the saving of souls." 
It is important to emphasize the following point: “It is not the role of the Pastors of the Church to intervene directly in the political structuring and organization of social life. This task is part of the vocation of the lay faithful, acting on their own initiative with their fellow citizens" (Catechism 2442). 
5. Economic activity and social justice
“Human work proceeds directly from persons created in the image of God and called to prolong the work of creation by subduing the earth, both with and for one another (cf. Gen 1: 28; Vatican Council II, Const. Gaudium et spes , 34; John Paul II, Enc. Centessimus annus , 31). Hence work is a duty: 'If any one will not work, let him not eat' ( 2 Thess 3:10; cf. 1 Thess 4:11). Work honors the Creator's gifts and the talents received from him. It can also be redemptive" ( Catechism 2427). By working in union with Jesus, we collaborates with the Son of God in his redemptive work. Work is a means of sanctifying persons and earthly realities, animating them with the Spirit of Christ (cf. Ibid. ). 
In working, “Everyone has the right of economic initiative; everyone should make legitimate use of his talents to contribute to the abundance that will benefit all and to harvest the just fruits of his labor. He should seek to observe regulations issued by legitimate authority for the sake of the common good (cf. John Paul II, Enc. Centesimus annus , 1 May 1991, 32; 34)" (Catechism 2429).  Responsibility of the state : “Economic activity, especially the activity of a market economy, cannot be conducted in an institutional, juridical, or political vacuum. On the contrary, it presupposes sure guarantees of individual freedom and private property, as well as a stable currency and efficient public services. Hence the principal task of the state is to guarantee this security, so that those who work and produce can enjoy the fruits of their labors and thus feel encouraged to work efficiently and honestly." 
Those responsible for business enterprises “have an obligation to consider the good of persons and not only the increase of profits. Profits are necessary, however. They make possible the investments that ensure the future of a business and they guarantee employment" (Catechism 2432). Those directing businesses “are responsible to society for the economic and ecological effects of their operations." 
“Access to employment and to professions must be open to all without unjust discrimination: men and women, healthy and disabled, natives and immigrants (cf. John Paul II, Enc. Laborem exercens , 14 September 1981, 19; 22-23). For its part society should, according to circumstances, help citizens find work and employment (cf. John Paul II, Enc. Centessimus annus , 48)" ( Catechism 2433). “A just wage is the legitimate fruit of work. To refuse or withhold it can be a grave injustice" (Catechism 2434).  Social justice : this expression came into use in the 20th century to refer to the universal dimension problems of justice had acquired. “Society ensures social justice when it provides the conditions that allow associations or individuals to obtain what is their due, according to their nature and their vocation" (Catechism 1928).
Justice and solidarity between nations : “Rich nations have a grave moral responsibility toward those which are unable to ensure the means of their development by themselves or have been prevented from doing so by tragic historical events. It is a duty in solidarity and charity; it is also an obligation in justice if the prosperity of the rich nations has come from resources that have not been paid for fairly" (Catechism 2439).
“Direct aid is an appropriate response to immediate, extraordinary needs caused by natural catastrophes, epidemics, and the like. But it does not suffice to repair the grave damage resulting from destitution or to provide a lasting solution to a country's needs" (Catechism 2440).
It is also necessary to “reform" international economic and financial institutions so that they will make possible and promote equitable relations with less developed countries (cf. ibid ; John Paul II, Enc. Sollicitudo rei socialis , 30 December 1987, 16).
6. Justice and charity
Charity— forma virtutum, the form of all the virtues —is at a higher level than justice. It is shown not only, or even principally, by giving more than is owed in strict justice. Charity consists above all in giving oneself (since that is what love is), and must always accompany justice, enlivening it from the inside. This union of justice and charity is shown, for example, in giving what is owed with joy, in a concern not only for the rights of others but also for their needs, and generally in practicing justice with refinement and understanding. 
Justice must always be informed by charity. It is fruitless to try to resolve the problems of people living together simply with justice understood as an anonymous “adequate functioning" of social structures: “When you are dealing with problems, try not to exaggerate justice to the point of forgetting charity" (St Josemaria, Furrow 973).
Justice and charity are both required when caring for those in need (the poor, the sick, etc.). The situation of society will never reach the point where personal attention to the material and spiritual needs of one's neighbor is superfluous. Carrying out works of mercy, both material and spiritual, will always be necessary (cf. Catechism 2447).
“Love—charity—will always be necessary, even in the most just of all societies. No political order, however just it may be, can make service prompted by love superfluous. Anyone who wants to leave out love, is going to neglect man as a human person. There will always be suffering calling for advice and help. There will always be loneliness. There will always be situations of material need necessitating help that shows concrete love for one's neighbor. The state that wants to provide everything, that takes over everything, ends us as a bureaucracy that cannot ensure the most essential need of suffering man—of any human being: an affectionate personal attention." 
Human misery draws down the compassion of Christ the Savior, who wished to take it upon himself, identifying himself with the least of his brothers (Mt 25:40). This is why those who suffer in misery are the object of a preferential love on the part of the Church, which, since the very beginning, has never ceased working to alleviate their suffering and to protect them (cf. Catechism 2448).
Basic bibliography Catechism of the Catholic Church 2401-2463.
St Josemaria, “Open to God and Man," in Friends of God , 154-174.
 This fact takes on special moral relevance in cases of real danger where one must make use of the goods of others as a prime necessity.
 The twentieth century saw the sad consequences, both economic and social, of this ideology.
 Cf. John Paul II, Enc. Centessimus annus , 1 May 1991, 10; 13; 44.
“Regulating the economy solely by centralized planning perverts the basis of social bonds; regulating it solely by the law of the marketplace fails social justice, for 'there are many human needs which cannot be satisfied by the market' (John Paul II, Enc. Centessimus annus , 34). Reasonable regulation of the marketplace and economic initiatives, in keeping with a just hierarchy of values and a view to the common good, is to be commended" ( Catechism 2425).
 Cf. St Josemaria, The Way , 631.
 Distributive justice spurs those governing society to distribute the common good, to assign honors or jobs to those who deserve it, without giving in to favoritism.
 John Paul II, Enc. Sollicitudo rei socialis, 30 December 1987, 38.
 “Those who, directly or indirectly, have taken possession of the goods of another, are obliged to make restitution of them, or to return the equivalent in kind or in money, if the goods have disappeared, as well as the profit or advantages their owner would have legitimately obtained from them. Likewise, all who in some manner have taken part in a theft or who have knowingly benefited from it—for example, those who ordered it, assisted in it, or received the stolen goods—are obliged to make restitution in proportion to their responsibility and to their share of what was stolen" (Catechism 2412).
In cases where one cannot locate the owner of some good, the person possessing it in good faith can keep it in his possession; whereas something possessed in bad faith —something stolen, for example—must be given to the poor or to welfare work.
 Cf. John Paul II, Enc. Sollicitudo rei socialis , 41.
 Vatican Council II, Const. Gaudium et spes , 76; cf. Catechism , 2420.
 “Social action can assume various concrete forms. It should always have the common good in view and be in conformity with the message of the Gospel and the teaching of the Church. It is the role of the laity 'to animate temporal realities with Christian commitment, by which they show that they are witnesses and agents of peace and justice' (John Paul II, Enc. Sollicitudo rei socialis , 47)" ( Catechism , 2442). Cf. also John Paul II, Enc. Sollicitudo rei socialis , 42.
“A priest, by virtue of his teaching mission should preach the Christian virtues, and their practical demands and manifestations in the concrete circumstances of the lives of the men to whom he ministers. He should, also, teach men to respect and esteem the dignity and freedom with which God has endowed the human person, and the special supernatural dignity which a Christian receives at Baptism.
“No priest who fulfils this duty of his ministry can ever be accused, except through ignorance or bad faith, of meddling in politics . Nor could it be said that his teaching interferes in the apostolic task which belongs specifically to the laity, of ordering temporal structures and occupations in a Christian fashion" (St Josemaria, Conversations , 5).
 “Professional work—and working in the home is also a first-class profession—is a witness to the worth of the human creature; a chance to develop one's own personality; a bond of union with others; a fund of resources; a way of helping in the improvement of the society we live in, and of promoting the progress of the whole human race....
“For a Christian, these grand views become even deeper and wider. Because work, which Christ took up as something both redeemed and redeeming, becomes a means, a way of holiness, a specific task which sanctifies and can be sanctified" (St Josemaria, The Forge , 702). Cf. St Josemaria, Christ is Passing By , 53.
 “Carry out all your duties as a citizen. Do not try to get out of any of your obligations. Exercise all your rights, too, for the good of society, without making any rash exceptions.
“You must give Christian witness in that also" (St. Josemaria, The Forge , 697).
 John Paul II, Enc. Centesimus annus , 48. Cf. Catechism , 2431. “Another task of the state is that of overseeing and directing the exercise of human rights in the economic sector. However, primary responsibility in this area belongs not to the state but to individuals and to the various groups and associations which make up society." ( Ibid. )
 John Paul II, loc. cit. , 37.
 “'Remuneration for work should guarantee man the opportunity to provide a dignified livelihood for himself and his family on the material, social, cultural and spiritual level, taking into account the role and the productivity of each, the state of the business, and the common good' (Vatican Council II, Const. Gaudium et spes , 67, 2)" ( Catechism 2434).
 “There is a long road to travel from the demands of strict justice to the abundance of charity. And there are not many who persevere to the end. Some are content to go as far as the threshold: they leave aside justice and limit their actions to a bit of welfare work, which they define as charitable, without realising that they are doing only a small part of what in fact they have a strict duty to do. And they are as satisfied with themselves as the Pharisee who thought he had fulfilled the law perfectly because he fasted twice a week and gave tithes of all he possessed" (St. Josemaria, Friends of God , 172). Cf. Ibid. , 83; St Josemaria, The Forge , 502.
 Benedict XVI, Enc. Deus caritas est , 25 December 2005, 28.