The people of Ontario are governed by two kinds of law: the common law and statutory law. The common law is the law as pronounced by judges on a case by case basis, “judge-made law.” The origins of the common law lie in the thousand year evolution of it in England. Today, it remains a major source of the rules and principles of our legal culture. The law of contract and the law of negligence, both important areas governing our lives, are based on the common law of England. By its very nature, judge-made law creates new common law on a slow incremental basis. While judges may be sensitive to the times in which they live, there are rarely broad sweeping changes that occur in the common law because judges must respect the precedent value of previous decisions.
The legislature is the source of legislation, or statutory law, which also governs our lives. Significant legal or policy changes may be brought about by legislation enacted by a particular government. A recent example is the federal legislation to recognize same sex marriages prompted by the Ontario Court of Appeal which had already decided that the common law definition of marriage was in conflict with the Charter, a statutory law.
Statutory law and common law affect each other. Legislation may codify the common law giving statutory force to common law principles without completely displacing the common law. For more than a century, criminal law has been codified in the Criminal Code but the common law concepts of mens rea (intent) and natural justice continue to influence the jurisprudence. Legislation may conflict with the common law and displace it to the extent of the conflict. An example is the Occupiers’ Liability Act, discussed in my previous legal column, which replaced the common law duty of care required of occupiers of premises. Ironically, most rules of statutory interpretation are judge-made rules often designed to preserve the common law from legislative encroachment. A basic rule of statutory interpretation is the presumption that the legislature does not intend to change the common law unless expressly stated in the legislation. Thus, in the Occupiers’ Liability Act, the statute expressly states that “this Act applies in place of the rules of common law.”