Judicial precedent is the process whereby judges follow previously decided cases where the facts or point of law are sufficiently similar.
It involves the following principles: First, stare decisis, which means to stand by the decided, whereby lower courts are bound to apply the legal principles set down by superior courts in earlier cases and appellate courts follow their own previous decisions. For example: The High Court must follow decisions of the Court of Appeal, which must follow decisions of the House of Lords.The Court of Appeal must also follow its own previous decisions. Secondly, the binding part of a previous decision is the ratio decidendi (reason for the decision) and it must be followed by judges in later cases. Anything said obiter dicta (by the way) in the original case is merely persuasive because it was not strictly relevant to the matter in issue and does not have to be followed.
For example: In Donoghue v Stevenson, the claimant suffered food poisoning after drinking from an opaque bottle of ginger beer which contained a dead, decomposing snail.The House of Lords held that a manufacturer owed a duty of care to the consumer that products are safe because the circumstances prevented the consumer from discovering any defects. This is the ratio and Lord Atkin’s “Neighbour Test” was obiter. Where there is no existing precedent, the court will “declare” the law and the case will become an original precedent, eg: Airedale NHS Trust v Bland, where the courts were asked to decide if food and treatment could be lawfully withdrawn from a patient in a persistent vegetative state, and thus allowed to die.
