Diploma in Legal Studies: Sources of Law, Court Hierarchy and Precedent
This domain tests the machinery of Irish law rather than a single substantive subject: whether you can name the source of a rule, place a court correctly in the hierarchy, and apply precedent and the canons of interpretation to a short problem with Irish authority.
Sources of law
- Bunreacht na hÉireann 1937 is supreme: an inconsistent law is invalid to that extent. Article 15.2.1° reserves law-making to the Oireachtas; Article 34 vests judicial power in the courts.
- Legislation: Acts of the Oireachtas and statutory instruments made under delegated powers.
- Pre-1922 common law and equity continued in force under Article 50.
- EU law binds the State through Article 29.4.6° and s 2 of the European Communities Act 1972.
Courts and precedent
District Court → Circuit Court → High Court → Court of Appeal (created in 2014 by the Thirty-third Amendment) → Supreme Court. A higher court binds the courts beneath it; only the ratio decidendi binds, while obiter dicta persuade. High Court judges are not bound by one another but normally follow; Circuit and District judges are bound by High Court ratios.
Interpretation
Courts use the literal, golden and mischief approaches and prefer a reading consistent with the Constitution - the presumption of constitutionality and the double construction rule in East Donegal Co-operative v Attorney General [1970] IR 317.
Worked example
A High Court judge hears a claim. Counsel relies on a sentence in a recent Supreme Court judgment saying an exclusion clause "could never be enforceable", though that appeal was decided on a limitation period.
Reasoning: the sentence was not necessary to the decision, so it is obiter and not binding, though highly persuasive; the judge should engage with it and explain any departure. A ratio of another High Court judge would not bind her either, but either would bind the Circuit and District Courts.
Traps
The commonest lost marks come from treating Supreme Court dicta as binding, citing Article 15.2.1° as the EU-law provision, or dating the Court of Appeal before 1937. The presumption of constitutionality merely favours a valid reading; it is not itself a finding of invalidity, which only a court may make.