It may surprise new law students to learn that there is no universal agreement as to what counts as a “source of law“ in the English legal system. There is no dispute that primary and delegated legislation are valid sources of law and that they are both superior to another valid source – case law. Gary Slapper and David Kelly in their book “The English legal System” list books of authority and “custom” as other sources of law, and other authors include less formal documents such as codes of practice, and more nebulous concepts such as “the Royal prerogative”. Whilst there are good reasons for counting these as legitimate sources of law, for the sake of simplicity we will focus on the two most significant sources: legislation and case law. And for this lecture our focus will be on case law.

There are two distinct legal traditions in the West - the common law legal systems of the UK and the US, and the civil law legal systems of France, Germany and other parts of the continent. It is accepted as a basic principle in common law systems that the legislative (Parliament) is not the only source of law. Common law systems are based on the acceptance that there is a framework of legal rules which the courts either clarify or create (there is some debate about which they actually do) and that these rules exist independently of any legislative instruments issued by Parliament or parliaments appointees. For example, in English law, the offence of murder has never been defined by a statute or statutory instrument, but comes from the statements made by judges sitting in court deciding what does and what does not constitute the offence of murder. There is some academic debate about whether judges make the common law or whether it has always existed and judges merely indicate how it applies to particular cases. This may seem like an arcane and pointless distinction but it is one which some academics believe is important because it impacts on the legitimate role of the judiciary in the modern legal system. For now let us assume that judges do “make” the common law.”

This clearly marks out case law as a significant source of law in the UK, but it an established principle that primary legislation emanating from parliament, and even secondary legislation created under the authority of parliament, “trumps” or is superior to case law. The Primacy of legislation over case law means that Parliament has to power to alter centuries’ old common law rules, and the courts must respect such parliamentary interventions. You will learn more about the legislative process and interpreting legislation in your second workshop.

But appreciate even at this stage that ultimately the courts apply the law in individual cases, and it is the courts which must make the final decision as to the meaning of legislation. For this reason, despite the primacy of legislation, the courts and case law provide the final say on every legal question which is subject to dispute. In this respect then case law is central to our English legal system.

Understanding the importance of case law in the common law legal system requires us first of all to deal with some basic definitions of common law. Unhelpfully for the new student of law this term is used by judges and academics to mean one of three things.

Clarifying “common law”
Common law = a classification of a legal system, representing the system used in England and Wales, the United States etc
Common law = a source of specific laws within a system. Laws which originate from decisions of judges
Common law = a branch of decisions of judges separate from the law of equity.

So in a common law legal system case analysis can play an important role in helping us to identify and clarify common law rules such as the definition of murder; but case law can also help us to understand statute law as well.

Definitions used in statutes are given effect in decided cases. We will look at this in more detail when