Lex and law: What’s the difference?

Although both words refer to law, lex comes from Latin and traditionally describes written rules and legislation. Law, by contrast, has Viking and Old English origins and developed through customs, traditions and community practice.

The origins of lex

In Roman times, lex referred to written laws created and enforced by government. As the Roman Empire expanded, legislation, written records and legal administration became central to maintaining order, shaping the legal systems that continue to influence many countries today.

The origins of law

The English concept of law developed differently. Rather than focusing on written rules, it evolved through customs that were accepted and followed by communities over generations. These unwritten traditions became the foundation of the English common law system.

How common law developed

As English legal institutions evolved, common law became distinct from the Roman legal tradition taught in universities across Europe. Courts developed legal principles through judicial decisions, creating a system built on precedent, reasoning and practical application.

Why this matters for lawyers today

Modern Australian lawyers work with both traditions every day. Legislation remains an essential part of legal practice, but so does the common law developed through court decisions. Understanding both perspectives helps lawyers think critically, interpret the law and apply it effectively in practice.