Judicial Law Making

In theory, judges do not make or change the law. The judge applies the law to the facts and makes the decision.   This would breach the principle of the separation of powers. The sole power to make law is vested in the Oireachtas (parliament). In principle, the judge’s role is limited to the application of the existing law to the facts of the particular case in hand.

Notwithstanding the formal principle that judges do not make law, they may face choices in evolving existing principles and/or applying them to new facts. In this limited sense, judges may “make” law. The common law has developed and continues to develop through the doctrine of judicial precedent.  In some cases, it might be fairly said that judges make the law as that the application of existing principles for new circumstances is not self-evident.

The notion that the judges do not ever make law is recognised in somewhat fictional and old fashioned.  There are many cases where a judge might legitimately decide a matter of law in one of a number of ways. In some cases, the judges may interpret the fact in one of a number of ways. This will often influence the way in this he articulates the law.

The courts may recognise that the process does involve making law although it will not usually express it in those terms.  The rules and principles set out in judicial decisions on the interpretation of legislation constitute a precedent, in the same way as common law decisions on points of law that are not embodied in legislation.

Common law rules are often amended by legislation.  A series of “civil” acts have made specific amendments to the pre-existing common law.

Common law can be overruled by legislation, except to the extent that the Constitution limits the possibility.  The Constitution takes priority to legislation made by the Oireachtas.

The Ratio Decidendi

The ratio decidendi is the principle of law on which the case is decided.  It is not the decision in itself.  It is the principle of law, of general application, which determines the case.

It can be difficult to identify the ratio decidendi of a judicial decision.  Traditionally, the matter was looked from the perspective of the judge who decided the case. The basis on which he expressly decided the case is determinative. However, decisions may have been too widely based or too narrowly based by the judge.  Where there are several judges in an Appeal Court, each may base his decision on different principles.  Accordingly, the overall basis of the decision is not easily discernible from a single judgment.

In modern times, the reason for the decision, ratio decidendi is commonly determined by what the court as a whole has said, as viewed in later cases.  What the judge or one particular judge has said is not necessarily the ratio decidendi. This objective approach allows a later judge to alter what might previously have been thought, to have been the ratio decidendi. Accordingly, the later judge may restrict the scope of an earlier case so that it does not apply to the current case before him /her.  Alternatively, he may widen the scope of the case so that it does apply and may thereby extend the scope of the previous case.

The ratio decidendi involves applying the law to the material facts. In deciding the ratio of a case, the facts that the judge treats as essential, either expressly or impliedly, are material.

Finding the Ratio Decidendi

It may be necessary to deduce the ratio from what is expressly stated. The ratio may or may not be set out in the headnote of the official law report.  The reporter\’s interpretation of the facts and the application of the law to them may be too narrow,  too broad or simply incorrect.

There may be more than one ratio (reason) for the decision in a case.  The view has been taken in some cases that where there are multiple reasons for the decision, the later courts may choose one over the other.  However, the predominant view is that where there are multiple reasons, each is binding.

It may be unclear as to what level of generalisation applies to the principle of the case.  This depends on the level of abstraction with which it is formulated.

In some cases, there may be no majority in favour of a particular basis or ratio decidendi.  If in this case, it loses a certain amount of its weight as a precedent, if the judges in superior court give radically different reasons for their decision, it may be difficult to extract any ratio decidendi.  They are consistent with the principle underlying the decision.  The case may be opened to several interpretations.


Precedent refers to the process by which a judge applies the principle of law to a case, by reference to the decisions of courts in earlier cases.  In another sense, “precedent” may refer to the earlier cases themselves and the principles of law embodied in them. The process involves the application of the principle of Stare decisis.  This is a Latin expression reflecting the notion that the courts should stand by existing decisions

The general position is that lower courts are bound to follow the decisions of superior courts. For example, the High Court must follow the principles in Supreme Court decisions,  even if it believes the decision is wrong in principle. A court will almost always follow the decisions of courts at the same level. Accordingly, a  High Court judge will almost always the decisions of other High court judges.

The principles in previous decisions which are binding are only those which are essential to the case.  This is expressed by the Latin term “ratio decidendi”, which broadly means the reason for the decision.  It is the principle of law that is critical to the outcome of the case.  This is justified by the fact that the judge has positively addressed his mind to the actual facts of the case.

The ratio decidendi is the law as applied to the key facts of the case. The reason for the decision may be stated at various levels of abstraction.  The ratio decidendi will seek to state the principle in the broadest terms so that immaterial distinctions are ignored. The ratio decidendi is based on the actual facts of the case as found by the court.

Inessential Comments / Obiter Dicta

Comments that are inessential to the outcome of the case are referred to as “obiter dicta”. They are not essential to the decision. These are comments made in the discussion of the law in the particular case, which is not essential to the decision. As hypothetical observations, they do not form part of the binding decision.  In some cases, particularly where there are multiple grounds on which the court has relied, it may be difficult to distinguish between reasons and basis of decisions which are essential and those which are collateral and therefore obiter dictum.

Obiter dicta may be a persuasive authority but are not binding. In contrast to the ratio decidendi, the judge has not addressed his mind to hypothetical facts, the subject to the obiter dicta comments. Obiter dicta are of different types and carry differing weight.  Where there are passing expressions of opinion on a point not expressly raised or in issue, they will be of less significance than where they are deliberate expressions of opinion made, after the case has been argued and the relevant legal authorities put. It is common for obiter dictum to be followed in later cases.

Notwithstanding the above distinction, the comments of the Superior Courts, in particular, the Supreme Court on points of law are of the utmost importance.  The Supreme Court may lay down the principles in broad terms, rather than limiting its comments to  the narrow facts of the case. It plays a conscious role as the ultimate authority on the law.

Sometimes  comments which may appear to be obiter dictum may, in fact, be part of the ratio decidendi.

Practical Limits of Precedent

It may happen often that multiple cases simply illustrate the same point.  In these instances, they are less useful in citation and argument to the court as a basis for a future decision.  Very many cases have very little precedent value and that they simply involve the application of a well-established principle.

In one sense, decided cases are illustrations of the application of the particular principle.  The common law system does not involve a rigid, blind adherence to precedent.  Precedent is not usually followed mechanically without any thought.

The principle of precedent brings a significant degree of certainty to the law. However, the courts will find ways of distinguishing cases refining them and narrow them where justice appear to require otherwise.

Over time the courts may develop new principles and extend old principles to meet new circumstances.  The massive number of cases illustrate that principles of law develop. The common law didnot developed as a coherent code from the theoretical basis.  It responds to a particular case.

Reversal / Overruling

Supreme Court are usually taken on points of law.  A higher level court may reverse the decision of a lower court, on a point of law.  Appeals to the The Supreme Court will not usually challenge the findings of fact made in the High Court unless there is no basis for the finding and it is patently wrong with reference to the evidence.  The rationale is that the Supreme Court has not seen the witness and did not directly appraise the facts.

“Overruling” occurs when a (usually) higher court overturns a decision on the law, made in an earlier case by another (usually lower) court. Higher courts may exceptionally not follow an earlier decision of a court at the same level, where there are overriding good reasons.  In principle, when a court overrules a decision, it has retrospective effect.  In effect, the earlier decision was never valid. This accords with the notion that judges declare the law or “find it”, rather than makes it.  It does not affect the particular decision in the earlier case

Formerly, the higher courts did not reverse themselves on points of law.  However, the UK courts and the Irish courts now accept that the rigid adherence to precedent may lead to injustice in particular cases. It may otherwise unduly restrict the proper development of the law. Therefore, although existing decisions are normally treated as binding, the highest court may depart from them, where it appears right to do so. The courts will not do so readily, as they are cognisant that the parties will have relied on the assumed law, in regularising their affair.

In some cases, it is said that the previous decision was made “per incuriam”.  This is where the earlier decision was wrongly made, in ignorance of a previous binding decision or applicable statute.  This sometimes, but rarely, occurs.  Where the precedent is binding, the lower court must follow it even if it considers it wrong. Even if a previous decision is not binding, it is usually persuasive and is likely to be applied.

Other Sources

If there is no direct authority in the form of a judicial precedent or applicable statute, other legal sources may be cited as a solution for the legal problem before the Court.

In the common law system, writings of scholars and academics are of less status and significance that in Continental civil law systems.  In those code based civil law systems, the statute is supreme, and cases are of persuasive authority only. Legal writing and the scholarship of jurists may be of persuasive authority. A similar approach is taken in some United States jurisdictions.  Very exceptionally Roman law or writings or Justinian Digest may be referred to in common law decisions.

Legal textbooks generally deal with matters in the abstract. Several legal works have gained stature in modern times.   In contrast, legal decisions deal with tangible facts which have been argued at length before the judges.  This is the justification for the greater weight and authority given to judicial authority and precedent, relative to legal textbooks.

Classic / Ancient Authorities

Some older authors are widely recognised as authoritative on the common law.  Influential authors include Glanville (12th Century), Bracton, Hengham (13th Century), Littleton, Statham (15th Century), Brooke, Fitzherbert, Stanford (16th century) and Chief Justice Coke, whose reports and four volumes of Institutes, were published in the 17th Century. Also influential are Plowden (16th Century), Hale (17th Century), Hawkins and Forster (18th Century).

Blackstone, the famous 18th-century legal author, wrote a four-volume Commentary on the Laws of England. Blackstone\’s Commentaries on the laws of England were based on lectures given in Oxford in the middle of the 18th Century. They were extremely influential, particularly in the formative years of the United States.

Scholarly Publications

Academic and scholarly publications may carry significant weight. The academic system of peer review generally ensures a very high standard. The Quarterly Law Review, the Cambridge Law Journal, the Modern Law Review and the Criminal Law Review are often relied on in the UK courts.  The principal legal academic publications in Ireland are the Dublin University Law Journal and the Irish Jurist.

The Judicial Studies Institute Journal is published by the Judicial Studies Institute is a scholarly legal publication aimed at the Irish judiciary. The Institute was established under the Court, and Court Officers Act to organise training, seminars and study visits for the judiciary. The main purpose of the JSI Journal is to provide Irish judges with relevant information and opinions.

The main Irish Practitioner\’s journals are the Irish Law Times (the Bar), the Incorporated Law Society’s Gazette (solicitors). They carry articles on practical legal problems by academic contributors and practitioners. A number of specialised legal journals have been published in particular areas of Irish law in recent years. They include the Commercial Law Practitioner and the Environmental Law Journal.


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