It is probably good to remind ourselves that Catholic Social Teaching concerns ethics or morals. In traditional Catholic teaching morality is about happiness and human flourishing. It is about human perfection and living our lives in accordance with our god given natures. Saint Irenaeus in the second century AD said that the glory of God is a man fully alive. In Catholic technical language this is the theory of natural law, which holds that morality is a function of human nature. This means reason can discover valid moral principles by looking at the nature of humanity in society. In this sense there is no specific Christian moral teaching as morality is accessible to all who are able to reason. This is important as in discussing ethical issues with people from other traditions or philosophical persuasions there should be a platform upon which we can seek common ground. Unless of course you are one of those who think that morality is all about doing things contrary to our nature and that God is an arbitrary dictator who out of the sheer hell of it sets us moral imperatives we are at pains to obey. But this is not the Catholic position and we are not saying we are right just because God told us so.

CST concerns public and political morals. It is the social and community dimension of the moral good. Just as we have individual morality which is concerned with the good of the individual, we have social morality which is concerned with the common good. Just as it is the duty of each person to seek their own good it is the duty of associations, groups, communities, states and in fact the world community to seek the common good or the good of all.

CST is founded on four fundamental principles often referred to as the permanent principles.

These are:

• The dignity of the human person;
• The common good;
• Subsidiarity;
• Solidarity.

All these permanent principles are founded upon two truths:

• All human beings are inherently valuable or blessed with a common dignity because they are made in the image of God;
• We are social beings intended, or by our very nature designed, to live together. We can only find our true happiness together: with others and for others.

To express this in another way all the permanent principles flow from the dignity, equality and unity of all humanity. We can see from all this that there is a harmony and unity between these principles and no principle can be looked at in isolation.

CTS is sometimes thought to be a novel development but it is not. It is simply an expression of the Gospel and its values; although the language that has been adopted starts fairly recently in 1891 with the publication of Rerum Novarum. This is true for all theology which is an attempt to interpret the scripture and the Church's tradition in the light of contemporary problems.

So what is the common good? The common good is the complete development of all the people of the world. John XXIII describes it as 'the sum total of conditions of social living, whereby persons are enabled more fully and readily to achieve their own perfection.' (Mater et Magistra – "Mother and Teacher" (1961), paragraph 65.) This is a somewhat of an elusive concept and needs some work to understand.
When we refer to the common good we are at one level talking about those goods or things or circumstances which are needed in order for all to live fully human lives. However, rather than refer to sum total of goods we need, CST refers to the common good because it is common to us all in that:
(i) it is indivisible belonging to everyone in common and individually we do not have exclusive rights to any bit of it; and
(ii) we can only attain it by working together.
The idea therefore differs from that of Utilitarianism (or consequentialism) and its central maxim of pursuing the 'greatest good for the greatest number,' with which it is sometimes confused. The pursuit of the common good entrusts, both to the government and the Church, care for the greatest good of all persons, not just the greatest possible number. No individual is excluded from the common good. It is also therefore linked to the ideas of human dignity and authentic and integral human development, making them central aims of all societies. If one of us is suffering we are all diminished.

The demands of the common good are dependent on the social conditions of each historical period. Within each period there are common areas of focus:
(i) The commitment to peace;
(ii) The use (or abuse) and organization of the state's powers;
(iii) The need for a sound juridical system;
(iv) Protection of the environment;
(v) The provision of essential services (some of which are recognized as human rights):
• food,
• housing,
• work,
• education,
• access to culture,
• transportation,
• basic health care,
• freedom of communication and expression; and
• protection of human freedom.

The responsibility for attaining the common good rests not just on individuals but also on the state. This is the raison d'être for political authority. Families and groups cannot of themselves achieve the common good without the state. Part of the responsibility of the state is to harmonize different and sometimes conflicting social interests.

One of the key associated ideas relating to the common good is that of the universal destination of goods. "God destined the earth and all it contains for all men and all peoples, so that all created things would be shared fairly by all mankind under the guidance of justice tempered by charity." (Gaudium et Spes - Second Vatican Ecumenical council.) Each person must have access to the level of well-being necessary for his full development. It is a universal right to use the goods of the earth. All other rights including property rights are subordinated to this right.

This does not mean that there is no place for private property. The church has not become a full blown supporter of Marxism. It has tended to steer a middle path between the extremes of Marxism and laissez faire capitalism. There is a strong emphasis on the importance of private property in CTS. Man has the right to enjoy the fruit of his or her labour. Private property is an expression of man's freedom which is essential to his perfection and happiness. But private property has its limits. It is not an absolute right. It is a means to an end.

Lastly it is important to state that the Church has been pretty firm in emphasizing that the concept of the common good and the Church's option for the poor go hand in hand. The principal of the universal destination of goods requires that the poor, the marginalized and in all cases those whose living conditions interfere with their proper growth should be the focus of particular concern.

In conclusion, George Osborne encapsulated the main thrust of CTS when he famously said that, "we are all in this together". Or perhaps a better summary still would be to quote my favorite author Fr Herbert McCabe, "we are all in the shit together"; and as CTS would go on to say we have a collective duty to get us all out of it.