Introduction

There are three common sense reasons why it is desirable for courts to follow their own previous decisions as well as the decisions of other courts, namely:

consistency is generally regarded as an important aspect of justice, partly because simple fairness requires that similar cases should have similar outcomes and partly because it provides sufficient predictability to enable lawyers to advise their clients;

following existing decisions is efficient because it avoids the need to re-argue points of law each time they arise and, therefore;

judges following the decisions of other judges is an important of aspect of judicial comity (which simply means the mutual respect that judges have for each other).

However, the common law goes one stage further than simply saying it is desirable for judges to follow each other’s decisions: it says that, at least in some circumstances, judges are bound to follow decisions made in earlier cases. On the other hand, the courts recognise that a very strict doctrine of binding precedent would have the undesirable consequence of being excessively rigid. This might not only make it impossible for the courts to respond sympathetically to the particular subtleties of an individual case but might also prevent them from developing the law when it is desirable to do so.

It follows that presenting the advantages and disadvantages of the system of binding precedent in terms of a conflict between certainty and predictability on the one hand and flexibility and justice on the other is too superficial to be genuinely helpful. More particularly, sufficient certainty to enable reasonable predictability is itself a part of, rather than being opposed to, justice.

The apparent conflict between certainty and predictability on the one hand, and flexibility and justice on the other is, therefore, replaced with the need to strike a broadly acceptable balance which will normally require the courts to follow earlier decisions, while allowing a degree of flexibility, which can be exercised according to well-understood principles.

We must now consider how the doctrine of binding precedent tries to strike this balance. As we will see, there are two elements to the doctrine. One requires us to analyse individual judgments so that their component parts may be identified and assessed (what is it that is binding?), while the other requires us to analyse the hierarchy of the courts and (in some cases) their jurisdictions, in order to see which courts are actually bound.

We will consider each of these matters in turn.