What Is the Ratio Decidendi of a Case and What Factors Need to Be Taken into Account in Ascertaining the Ratio of a Decision?

“What is the ratio decidendi of a case and what factors need to be taken into account in ascertaining the ratio of a decision?”        

Introduction:

  The literal translation of ratio decidendi is “the reason for deciding”, however, its legal definition has not always been as straightforward.   With the exception of the word “malice”, it has been said ratio decidendi, is the most ambivalent term in law.^[1]  It has been described as ‘the rule of law upon which the decision is founded’^[2]  and the ‘authoritative element’^[3] of a judicial decision.  This ambiguity has led to debate and difficulty.  Determining the ratio decidendi has been described as an art rather than a scientific process.^[4]  This essay will discuss the meaning of ratio decidendi, the different interpretations of it and the factors needed to ascertain the ratio of a decision.

Defining Ratio Decidendi:

  The term ratio decidendi was not used extensively in English law prior to the nineteenth century and it is suggested that it came into use through canon law and continental usage.  Courts have not been bound by a single definition of the term, but have employed it as ‘a way to bridge the gap between reasoning by analogy and reasoning with rules’.^[5] 

“Classical” definitions of the term invoked the rule of law with descriptions such as ‘the rule of law on which a court’s decision is founded.’^[6]  This has since been refuted by Goodhart.  Goodhart held that it was not the rule of law set forth by the court which constitutes the ratio decidendi, as there may be no rule of law espoused in the opinion.^[7]  Goodhart instead proposed that the courts often outline their reasons too widely or, paradoxically, too narrowly in their statement of law.^[8]  Stone argued that Goodhart was attempting to form a prescriptive rather than a descriptive theory of ratio decidendi.  Stone contends that ratio decidendi has two different meanings: a descriptive meaning, which provides an explanation of the court’s reasoning and a prescriptive meaning that refers to the statement of law found in an earlier case, which that case prescribes as being the law for later courts to follow.^[9] 

  Ratio decidendi has also been effectively explained through case law.  In Ugbelase v Minister for Justice Cooke J held: ‘A previous judgment can only be said to be a precedent by reference to its ratio decidendi, the essential principle upon which the concrete decision is based.’^[10] This reference to the “essential principle” highlights a key aspect of the definition of ratio decidendi.  It is submitted that ratio decidendi is a flexible notion which is not so much a rule but rather a method employed to form a rule.^[11]

Factors to ascertain the ratio of a decision

  Goodhart held that the primary step in ascertaining the ratio decidendi is to determine the material facts on which the judge based their conclusion.^[12]  If there is no opinion in a judgment, or if the opinion does not contain a statement of facts, Goodhart held that one must assume that all the facts given in the report are material.  Goodhart held that we are bound by the judge’s affirmation of the facts, even though it may be evident that the judge has misstated them, for it is on the facts that the judge based their judgment.^[13] 

  Goodhart also proposed that it is necessary to determine what facts have been held to be immaterial, as the ratio depends as much on exclusion of facts as it does on inclusion.^[14] Goodhart’s final step is to ascertain whether or not it is a binding precedent for a subsequent case in which the ‘material’ facts are prima facie similar.  This, according to Goodhart, invokes double analysis.  First, the material facts in the precedent case must be stated and discovery of those which are related in the second case must be undertaken.  If these are identical, then the preceding case is a binding precedent for the second and the conclusion reached in the preceding case must also be reached in the second case.^[15] 

  Goodhart realised that this theory would be open to criticism, as one that finds the ratio of a case on its material facts leaves us with few legal principles.  Cross acknowledged that while “it is always essential…in order to arrive at the ratio decidendi of a case to consider the facts…it is sometimes necessary to do a great deal more.”^[16]  Stone also criticised Goodhart’s method, believing that his process amounted to choosing an appropriate level of generality.  Stone argued that if the ratio of a case is deemed to turn on the facts, and nine facts are found in the judgment, there could be as many rival rationes decideni as combinations of ‘material’ facts in it.^[17] 

  Stone argued that Goodhart’s method led someone to believe that a ratio is only prescriptive for a later case whose facts are on “all fours” in every respect.^[18]  Outside this range the question is whether in the later court’s view the presence in the instant case of some of the facts at varying levels of generality, is more relevant to its present decision than in the absence of them.  To Stone it is not a question of the “materiality” of facts to the decision in the earlier case imposing itself on the subsequent case, but ‘a question of the analogical relevance of the prior holding to the later case, requiring the later court to choose between possibilities presented by the earlier case.’^[19] It is the later court, examining the case in the light of the case that preceded it, which is the ‘arbiter of the appropriate level of generality.’^[20] 

  The arguments proposed by counsel in a case are also crucial in determining the ratio of a decision.  In Re Hetherington Browne Wilkinson CV stated that a court is not bound by a proposition the correctness of which was assumed by the earlier court, without it having been specifically considered.^[21]  A decision reached in ignorance of a statute or binding authority, known as a per incuriam decision, is also not considered to be binding.  Although the preceding court will have believed that it reached a ratio decidendi, the court’s ignorance of the earlier law deprives its finding of that status.  In other words: a relevant point has not been argued, and, therefore, has not been decided.^[22]