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Legal skills and debates in Scotland
Legal skills and debates in Scotland

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1.1  Finding the ratio decidendi

There were five law lords hearing this case in the House of Lords (the final civil appeal court for Scotland at this time). Three found in favour of Mrs Donoghue’s appeal, including Lord Atkin. The other two were Lords Thankerton and Macmillan. Atkin’s judgment is known as the leading judgment.

Lords Buckmaster and Tomlin dismissed the appeal, which means they decided in favour of the defendant Mr Stevenson that there was no legal duty of care owed to Mrs Donoghue. Their judgments are called dissenting opinions.

The result was a majority 3 : 2 decision in favour of Donoghue. A majority decision is enough to decide the law (and is one of the reasons an odd number of judges sit in appeal cases). It does not need to be a unanimous decision. Each lord delivered a separate judgment (although this is not always the case) and they often did not use the same process of reasoning or interpretation of the law to come to their conclusions.

Here we are interested in the process of reasoning by which this decision came about. This case is a good illustration of how logical reasoning is transformed into legal reasoning because even though each judge is attempting to answer the same question, using the same set of facts, and by looking at the same common law represented by previously decided cases, the route each judge takes is different and the decisions that they reach sometimes are different also.

The fact that the judges can come to different conclusions by applying the same previous cases to the same set of facts says something about how judges reason using the doctrine of binding precedent.

One ratio decidendi we might take from Donoghue is the ‘neighbour principle’. However, while this is the best-known aspect of the decision, it is a very wide principle that goes beyond the specific facts of the case, so it arguably was not part of the legal reasoning. This means it was not necessary to reach the decision that Stevenson owed a duty of care to Donoghue. We might alternatively argue that even though it is not a strictly legal principle, it was necessary for Atkin to come to his decision – he deduced his legal decision from a higher, moral principle. However, the ratio decidendi of a case is conventionally more specific and maintains the fiction that strictly legal reasoning has been applied to the case. In addition, the other two judges who came to the same ultimate decision did not refer to or endorse this principle, so it was not a common part of the reasoning of all of the majority judges. The ratio decidendi is usually a combination of what is agreed by all of the assenting judges, those who agreed with the decision in the leading judgment. A common description of the ratio decidendi of the case might therefore be found for Donoghue which is more specific to the circumstances of the case.

Read the extracts in Box 1, taken from the judgments of Lords Macmillan, Atkin and Thankerton, the three ‘majority’ judges in Donoghue who agreed that Mr Stevenson owed a duty of care to Mrs Donoghue in the case.

Box 1 Extracts from the judgments in Donoghue

Lord Macmillan

I have no hesitation in affirming that a person, who for gain engages in the business of manufacturing articles of food and drink intended for consumption by members of the public in the form in which he issues them, is under a duty to take care in the manufacture of these articles. That duty, in my opinion, he owes to those whom he intends to consume his products. He manufactures his commodities for human consumption; he intends and contemplates that they shall be consumed. By reason of that very fact, he places himself in a relationship with all the potential consumers of his commodities, and that relationship, which he assumes and desires for his own ends, imposes upon him a duty to take care to avoid injuring them.

Lord Atkin

A manufacturer of products, which he sells in such a form as to show that he intends them to reach the ultimate consumer in the form in which they left him, with no reasonable possibility of intermediate examination, and with the knowledge that the absence of reasonable care in the preparation or putting up of the products will result in an injury to the consumer’s life or property, owes a duty to the consumer to take that reasonable care.

Lord Thankerton

The respondent, in placing his manufactured article of drink upon the market, has intentionally so excluded interference with, or examination of, the article by any intermediate handler of the goods between himself and the consumer that he has, of his own accord, brought himself into direct relationship with the consumer, with the result that the consumer is entitled to rely upon the exercise of diligence by the manufacturer to secure that the article shall not be harmful to the consumer.

You should now move on to Activity 1, which explores the extracts of the judgments in Box 1.

Activity 1 Finding the ratio decidendi

Timing: (Allow 25 minutes)

Part One

Find as many things as you can that all of the statements in Box 1 have in common. Note your findings in the table provided. Also make a note of any additions or limitations mentioned. The words might not be exactly the same in each case but the meaning of the words should be similar. For example, they all mention that what is manufactured is a product or an article, but while Atkin does not narrow it down further than this, Macmillan limits it to ‘food and drink’ and Thankerton specifies ‘article of drink’ only. The agreed part is the most restricted definition of the product, which is a drink.

Points agreedAdditions or limitations
The object is a drink.Macmillan (food and drink); Atkin (product generally).
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Part Two

Having completed your table try to use the things that they have in common to put together a short statement that might be a possible agreed ratio decidendi for the case.


Your table should look something like this:

Points agreedAdditions and/or limitations
The object is a drinkMacmillan (food and drink); Atkin (product generally)
A manufacturerNone
Intended for the consumer – placed on the marketNone
In the original form – to exclude interference or examinationNone
Duty of care owed to the consumerThankerton describes this as an entitlement ‘to rely upon the exercise of diligence by the manufacturer’

From this table, your statement of the possible ratio decidendi will look something like this:

A manufacturer of a drink who intends it for the consumer in its original form, and manufactures it in such a way to exclude the possibility of interference or examination prior to being consumed, owes a duty to take care to the consumer.

This is reasonably similar to the shorter of the explanations offered by the lords. Ratio decidendi statements taken from individual cases are often very specific and tied to a limited set of facts. A wide ratio decidendi such as the ‘neighbour principle’ is often resisted because it can lead to unforeseen consequences and might be found to apply to unintended situations.

Activity 1 produced one example of what the ratio decidendi for Donoghue might be. Hopefully you will have seen from this that it is not straightforward.

If you were to read the full case report to find the ratio decidendi, you would have to look through more than 60 pages of court report, including five different judgments, to agree what the ratio decidendi is.

How to interpret the judgments is even more confusing when the obiter dicta comments of the judges that surround the ratio decidendi,and which are persuasive as to the current status of the law, are taken into account. You will see this very clearly in the next section, where we will consider how the lords in Donoghue included the precedent case law in their reasoning process.