Legal Glossary

The physical element of a crime — the guilty act. For criminal liability, both actus reus and mens rea must typically be proven. It can include acts, omissions (where there is a duty to act), and states of affairs.

A fundamental principle of natural justice meaning 'hear the other side'. No person should be condemned without being given the opportunity to present their case. Central to judicial review and administrative law.

The three-stage test from Caparo v Dickman [1990] for establishing a duty of care in negligence: (1) reasonable foreseeability of harm, (2) proximity between the parties, (3) fair, just and reasonable to impose a duty.

Something of value exchanged between parties to a contract. A promise is only binding as a contract if supported by consideration — 'something for something'. Can be a benefit to the promisor or a detriment to the promisee.

A partial defence to tort claims where the claimant's own negligence contributed to their loss. Under the Law Reform (Contributory Negligence) Act 1945, damages are reduced by the proportion of the claimant's fault.

A legal obligation requiring a person to take reasonable care to avoid causing foreseeable harm to others. Established in Donoghue v Stevenson [1932] and refined by the Caparo test [1990]. The first element of a negligence claim.

So minor or trivial that the law does not concern itself with it. Often expressed as 'de minimis non curat lex' — the law does not concern itself with trifles. Used to dismiss claims involving negligible harm.

General Data Protection Regulation (EU) 2016/679. The EU's comprehensive data protection framework, granting individuals rights over their personal data and imposing obligations on controllers and processors. Applies extraterritorially to any entity processing EU residents' data.

An equitable court order requiring a party to do something (mandatory injunction) or refrain from doing something (prohibitory injunction). Granted at the court's discretion. Breach of an injunction constitutes contempt of court.

A legal action directed against a specific person, as opposed to a right enforceable against the whole world (in rem). Contractual rights are in personam — only binding on the parties to the contract.

The process by which courts supervise the exercise of public power. Courts do not substitute their own decision but assess whether the decision-maker acted lawfully, rationally, and fairly. Grounds include illegality, irrationality, and procedural impropriety (CCSU v Minister for Civil Service [1985]).

The philosophy and theory of law. Jurisprudence examines questions such as: What is law? What is the relationship between law and morality? What makes law legitimate? Major schools include natural law, legal positivism, and critical legal theory.

The right or capacity to bring an action before a court. A claimant must demonstrate a sufficient legal interest in the matter. In judicial review, an applicant must have a 'sufficient interest' in the matter to which the application relates (Senior Courts Act 1981, s.31(3)).

The mental element of a crime — the guilty mind. Can include intention, recklessness, or knowledge, depending on the offence. For most serious crimes, the prosecution must prove both actus reus and mens rea. Some offences are strict liability, requiring no mens rea.

Lord Atkin's formulation in Donoghue v Stevenson [1932]: you must take reasonable care to avoid acts or omissions which you can reasonably foresee would be likely to injure your 'neighbour' — persons who are so closely and directly affected by your act that you ought reasonably to have them in contemplation.

No one should be a judge in their own case. A principle of natural justice requiring that decision-makers be impartial and free from any conflict of interest. Central to judicial review and fair trial rights under Article 6 ECHR.

Remarks made by a judge 'by the way' — observations not essential to the decision. Obiter dicta are not binding precedent but can be highly persuasive, particularly when made by a senior court. Distinguished from the ratio decidendi, which is the binding part of a judgment.

Where a defendant does not desire a consequence but foresees it as a virtually certain result of their action. Distinguished from direct intent, where the consequence is the defendant's aim or purpose. Relevant in murder — see R v Moloney [1985] and R v Woollin [1998].

The doctrine requiring courts to follow earlier decisions of courts of the same or higher status. 'Stare decisis' — stand by what has been decided. A cornerstone of common law systems. The binding part of a case is its ratio decidendi.

A principle requiring that measures taken by the state must not be excessive in relation to the legitimate aim pursued. Central to EU law and ECHR analysis. Increasingly applied in English administrative law, though the precise relationship with Wednesbury unreasonableness is disputed.

The legal reason for a court's decision — the binding part of a judgment. Future courts must follow the ratio of a case from a higher court (doctrine of precedent). Identifying the ratio of a case is often a matter of significant legal debate.

The right under Article 17 GDPR for individuals to request erasure of their personal data. Established in EU law by Google Spain v AEPD [2014]. Applies where data is no longer necessary, consent is withdrawn, or data has been unlawfully processed. Not absolute — subject to competing rights and freedoms.

The capacity to have subjective experiences — in particular, the ability to feel pain and pleasure. The scientific and philosophical basis for recognising animal interests in law. Recognised in UK law by the Animal Welfare (Sentience) Act 2022 and in EU law by Article 13 TFEU.

Liability that arises regardless of fault — no intention, recklessness, or negligence needs to be proven. Applies in certain areas of criminal law (e.g. regulatory offences) and tort (e.g. the rule in Rylands v Fletcher [1868]). Justified on grounds of public protection and deterrence.

A civil wrong giving rise to a claim in damages. Distinct from contract (which requires an agreement) and crime (which is prosecuted by the state). Major torts include negligence, nuisance, trespass, and defamation. The law of tort is largely judge-made common law.

The test for oblique intent in murder: the defendant must foresee the consequence (death or GBH) as a virtual certainty — not merely probable or likely. Established in R v Moloney [1985] and confirmed by R v Woollin [1998]. Only then may a jury find intention.

A complete defence to a tort claim meaning 'to one who consents, no wrong is done'. The claimant voluntarily assumed the risk of harm. Requires both knowledge of the risk and genuine consent to it. Narrowly construed by courts — distinguished from mere knowledge of risk.