Sources of Law: Constitutions, Statutes, Regulations, and Case Law
The hierarchy
Sources rank in authority: constitution > statute (primary legislation) > delegated/administrative regulation > case law interpreting each. A rule lower in the hierarchy that conflicts with a higher one is invalid to the extent of conflict. Constitutions establish institutions, allocate power, and protect rights; statutes are enacted by legislatures; regulations are made by agencies under delegated authority and must stay within the enabling statute (ultra vires if not); case law fills gaps and interprets text.
Interpretation and precedent
Statutory interpretation uses textual (plain meaning), intentional (legislative history), and purposive (underlying aim) approaches, plus canons such as expressio unius (mention of one excludes others) and the rule that specific provisions prevail over general ones. Stare decisis requires courts to follow binding precedent from higher courts in the same hierarchy; distinguishing avoids precedent by showing materially different facts; overruling is reserved for higher courts. Persuasive authority (sister jurisdictions, scholarly commentary) is not binding.
Traps
- Treating a regulation as equal to a statute; agencies cannot exceed delegated power.
- Assuming all precedent binds; only precedent from a superior court in the same jurisdiction binds.
- Confusing overruling (a court rejecting its own or a lower court's earlier rule) with reversing (an appellate court changing the outcome of the case below).
- Ignoring commencement dates and transitional provisions; statutes may not apply retroactively.
Rule of thumb
When sources conflict, move up the hierarchy; when a statute is ambiguous, start with the text, then purpose, then history.
Worked example
A statute bans "vehicles" in a park; a regulation purports to permit bicycles. The regulation is ultra vires because it contradicts the enabling statute. A prior case holding skateboards are vehicles is persuasive but distinguishable if the facts concern a mobility scooter.