Laws made in Parliament are intended to cover wide and important tracts of social and economic activity. Common law is used when there is no specific Parliamentary legislation to cover the details of the problem facing the court.
The kind of case dealt with under common law is as follows: an indignant man wants to 'claim damages', in this case for his personal suffering. He is called the claimant. He comes to court accusing the cooks in a restaurant of adding dangerous mushrooms to the soup which have led to his suffering food poisoning. He declares that he might have died! There are plenty of questions here to sort out: Did the man actually suffer from food poisoning - or did he have some other problem? If he suffered from food poisoning, was his meal at this restaurant the cause? Were there dangerous mushrooms in the soup? Could the cooks have identified them as dangerous? Did the cooks fail to carry out their duties properly? Is the owner of the restaurant legally responsible? In this case, the judge in the court cannot simply decide what to do on the basis of what he thinks is fair and full of common sense. He has to find out what happened in a similar earlier case; and what was decided on that earlier occasion would have been based on an even earlier decision. However, since no case is exactly the same as a previous case, the lawyers both for the angry victim and the worried restaurant owner will argue that this case must be interpreted in such-and-such a way because of its particular features. For instance, the mushrooms were picked in the woods, not bought in a shop. That's different. Also somebody else ate the same soup and was not ill; but these mushrooms only affect some people... The judge's job is to sort all this out, and then, in his report, explain exactly why he departed from precedent (and established a new precedent).
Common law tends to reflect the efforts throughout the ages to make fair arrangements between contracting parties who are basically equal under the law. Although in the reign of Henry II many English people were serfs who were bound to their lords, in the reign of his son, King John, the great charter, Magna Carta (1215) began to express the idea that Englishmen had rights which could not be ignored or taken away by the King. In particular, no English subject could be arrested without charge; in other words the King or another powerful person did not have the power to lock him up simply because he was doing something they did not like. The notion that we are entitled to our 'own person', our freedom from arbitrary arrest is called Habeas Corpus (Latin for 'You have the body') Under Habeas Corpus, a prisoner can challenge the courts to let him go free if no clear explanation has been given to him as to why he has been arrested, or if he is arrested but not given a trial. This right, available to ordinary people has been disliked by the powerful in every century; in almost every decade some Minister or other powerful person tries to block it. They still try (usually on the grounds of national security). But the judges are obliged to uphold Habeas Corpus. It is one of the legal ways in which we can restrain a too-powerful government.
So judges adapt old common law, step by step, slowly. Although Parliament can make new laws to override old ones, the process takes a long time, and meanwhile legal decisions are embedded in precedents which may date back for centuries. Often we feel irritated or embittered by obvious stupidities in the law which cannot take proper account of a modem situation. But there are advantages. First of all, when Parliament passes a new law, it has to be examined very carefully to make sure that it does not contradict previous law unless there is full and clear intention to do so. Ideally, there should be no muddle. The Russian habit of Presidents declaring a law on Day One and rescinding it on Day Two does not happen here. Ministers change their minds, of course, about emergency regulations. ('Should we give pensioners extra money for heating this month because it has been abnormally cold? Yes! No! Yes!') But this is an emergency action. It does not affect the law.
Secondly, importantly, the existing Law cannot be overturned by a Government. In Britain the judges are not political appointments, as they are in America. Senior judges are chosen basically by the judges themselves. This system has its own problems, but it keeps them independent of political power and it ensures that, as guardians of the law, they can always say 'No' to the Prime Minister, the Cabinet, or a particular Minister who wants some policy carried out quickly. Parliament does make and change laws as I have explained, but Parliament is not the Government; it contains strong and articulate opposition parties and the issues will be debated and argued in detail.
So it should be clear that the role of senior judges is crucial to the interpretation and upholding of the law. Parliament can change the law, but the Law is always above Government. And Parliament consists of the People's elected representatives. So -indirectly but clearly, we are responsible for our Law.
Recently there has been one big change to this system. As members of the European Union we have had to import significant parts of European Law which is - unlike ours -based on the idea of a Legal Code. We have also imported and ratified the European Convention on Human Rights. European law and the Convention on Human Rights have been founded on principles and worked out systematically. That's fine, but it is not how our Law works, so there have been many difficulties for the judges in basing their judgements on precedent in one case, on principles in another, and in not being sure which way to go in a third case.
Our senior judges are serious and professional people. Their view of life may be sometimes limited, and of course they have their own personalities and prejudices, but professionally they make their decisions 'without fear or favour'. I think it is true to say that our judiciary is not corrupt.
What about the content of British law? Its provisions and principles affect almost every area of public and private life. You will probably need a lawyer if you wish to buy, sell or rent a house. The law sets out the arrangements for marriage, divorce and custody of the children of divorced couples. It decides how you may distribute your goods when you die, imposes limits on how fast you may drive your car, and on what breeds of dogs you may own. It explains what taxes you must pay, and the benefits to which you are entitled. It describes your duties towards other people and organisations -whether you are their employer, doctor, hairdresser, grocer or host for supper. Similarly, it tells you what you can expect of them, what remedies you may be entitled to, if they break their obligations to you. If a guest breaks his leg on a loose floorboard in my house, I am liable to pay him compensation. If I fall and break a leg on the city pavement because some paving stone has been left lying in my way, I can sue my local Council. (However, the British, unlike the Americans, do not devote much of their time suing each other. It is generally considered to be an activity which makes money for lawyers rather than anything else.)
This law which reaches into every comer of our lives is by and large respected. By world standards, we are a law-abiding people. Perhaps this is because the whole basis of Common Law is a series of contracts between free people. It is not hierarchical like most European law. Perhaps we feel, deep down, comfortable with regulations founded on the idea that they express what 'we' -as members of our community - have agreed with 'us' - as members of our community.