Skip to main content

About this free course

Become an OU student

Download this course

Share this free course

Judges and the law
Judges and the law

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

7.2 Statute law and common law

The ‘common law’ means the substantive law and procedural rules that have been created by the judges through the decisions in the cases they have heard. I have here lumped together two types of common law: substantive law and procedural law. Let me explain the difference between them.

A substantive rule is a rule about our behaviour, for example, that we cannot commit murder or that we will be forming a contract if we do such-and-such on an email exchange. These substantive rules are different from procedural rules, as the latter govern simply how things should be done. For example, regardless of what sort of case is in court, the rules governing the admission of evidence into court are the same.

Statute law, on the other hand, refers to law that has been created by Parliament in the form of legislation. Although there has been a significant increase in statute law in the twentieth and twenty-first centuries, the courts still have an important role to play in creating and operating law generally and in determining the operation of legislation in particular. This is despite the fact that there is no legislative or express democratic authority for the court to be law-makers.

Activity 16 requires you to read an article which discusses the role of Parliament and the role of the courts in making legal rules. This article is longer than previous Readings, but don't let this daunt you. You will be familiar with the ideas which are discussed in the Reading.

Exercise 1 then asks you to apply your understanding and knowledge of the common law and summarise the importance of the common law system being both flexible and certain. You are then asked to weigh and evaluate the arguments and say whether you think the ‘judicial computer’ discussed in Reading 6 should replace the common law. This is not a question of arriving at the ‘right answer’ any more than there is a scientific ‘right answer’ to what is the best political party or the best soup! It is about being able to give reasons for a viewpoint you have arrived at.

Activity 16 Making law: the use of precedent

Timing: 1 hour 0 minutes

Now click here [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] to read the document Reading 6: ‘The law factories’ and complete the three exercises (PDF, 0.2mb, 5 pages).

Exercise 1

Timing: 0 hours 20 minutes

Explain why there is a need for a balance between certainty and flexibility in common law. Do you think it would be better if the common law were replaced by a ‘judicial computer’ like that depicted in Reading 6?



Certainty is needed to allow people to plan their behaviour and to allow lawyers to advise their clients. Thus, in 1995 the House of Lords did not change the doli incapax rule concerning the criminal liability of children. Also, in the case of the soldier Private Clegg, in 1995 the Lords declined to make any changes to the law of self-defence.

Therefore, the legal system needs to balance these two competing, but equally legitimate, aims. If a ‘judicial computer’ were adopted this would guarantee certainty but remove all flexibility from the legal system.


The common law must be flexible in order to respond to changing times. Lord Hobhouse noted that the common law develops ‘as circumstances change and the balance of legal, social and economic needs changes’. For example, in R v R (1992), the House of Lords saw fit to abolish the then 256-year-old rule against a charge of marital rape. Also in Pepper v Hart (1993), the Lords’ Appellate Committee swept away a 223-year-old constitutional rule that had prevented Hansard being consulted by law courts in aid of statutory interpretation.

Exercise 2

Timing: 0 hours 20 minutes

Having considered why certainty and flexibility are important, please now describe how certainty and flexibility are introduced into the common law system.



The binding nature of the ratio decidendi creates a foundation for certainty.


Flexibility is introduced by:

  • Overruling – where higher courts can overrule lower courts in circumstances where the later court thinks that the earlier court gave an erroneous analysis.

  • Distinguishing – where a lower court is able to point to material differences that justify the application of different principles.

  • Departing – where, in certain circumstances, a court can depart from its own previous decision. This can be done, for example, where ‘times have changed’ since the earlier decision that seems to bind courts today.

Until 1966 the House of Lords was bound by its own decisions. In 1966, the Lord Chancellor issued a Practice statement which stated that the House of Lords may depart from its own previous decision where it is right to do so. The reasons given were to avoid injustice and restrictions on the proper development of the law.

The Court of Appeal can depart from previous decisions if one of the exceptions in Young v Bristol Aeroplane Co. Ltd (1944) is established. The Court of Appeal may also depart from a previous decision where this decision was per incuriam (through lack of care) because it was made in ignorance of relevant legislation or House of Lords’ decision with the result that the decision is demonstrably wrong. In criminal cases the Court of Appeal may depart from a previous decision if to follow it would lead to an obvious injustice.

Exercise 3

Timing: 0 hours 20 minutes

Again based upon your knowledge and understanding of this course, summarise the advantages and disadvantages of a system of precedent. You should take some time to revise the notes you made from the previous activities, and perhaps reread part of the course.


Did you include the following advantages and disadvantages?


  • Precedent allows the legal system to become more ‘just’ as the law is certain – so everyone can know what the law says about any topic.

  • The certainty of precedent is tempered by the flexibility judges have to not follow previous cases.

  • Precedent is more practical – the law can modernise without the need for Parliament to enact new laws.


  • The development of the law is contingent on ‘accidents’ of litigation, i.e. the courts only rule on the law in the cases that happen to get brought by citizens.

The development of the law is hindered by the need for certainty.