INTRODUCTION

The main subject of the present chapter is the bindingness of decisions inter partes on matters decided by a court (or an arbitral tribunal: on the latter, 17.01 ff, vol II). This is known as estoppel per rem judicatam, or res judicata. This form of estoppel bars successive litigation of the same claim or issues between the same parties. It concerns ‘claim or issue preclusion’. The underpinning maxims are: nemo debet bis vexari pro una et eadem causa and interest res publicae ut fi nis litium sit (‘no one should be disturbed twice in the same matter’ and ‘it is in the public interest that lawsuits should have an end’). The res judicata doctrine has various manifestations: cause of action estoppel, issue estoppel, and the doctrine of merger (the need to bring all claims for compensation, arising from the same event, in a single action). Furthermore, the desire to achieve closure in civil proceedings inspired the English courts to recognise an extended principle: the rule in Henderson v. Henderson (1843) requires litigants to bring to the original action all reasonably convenient issues, and not to attempt in successive litigation to raise points which might have been conveniently examined in the earlier case. (In fact ‘estoppel’ is a general doctrine, although there are many variants of estoppel in English law. It prevents a party from acting inconsistently with a representation, whether by words or conduct. This concept has been recognised by the UNIDROIT Principles of International Contracts.)

RECOGNITION OF FINALITY AS A HALLOWED PROCEDURAL PRINCIPLE

English trial judges (whether sitting in the High Court or a lower first instance court) will have attended meticulously to the rival submissions and evidence and reached a careful decision. Against this background it is not surprising that the courts have emphasised the principle of finality. Thus in Smith v. Brough (2005) Brooke LJ noted that: ‘it is a fundamental principle of our common law that the outcome of litigation should be final.’