The classic dissenting judgment of Lord Atkin arguing that parliament should be taken at its word and no more particularly when constitutional issues (we would talk now of human rights law).

‘These cases raise the issue as to the nature and limits of the authority of the Secretary of State to make orders that persons be detained under reg. 18B of the Defence (General) Regulations, 1939 . The matter is one of great importance both because the power to make orders is necessary for the defence of the realm, and because the liberty of the subject is seriously infringed, for the order does not purport to be made for the commission of an offence against the criminal law. It is made by an executive minister and not by any kind of judicial officer, it is not made after any inquiry as to facts to which the subject is party, it cannot be reversed on any appeal, and there is no limit to the period for which the detention may last. The material words of the regulation are as follows:
“If the Secretary of State has reasonable cause to believe any person to be of hostile origin or associations and that by reason thereof it is necessary to exercise control over him, he may make an order against that person directing that he be detained.”
They are simple words and as it appears to me obviously give only a conditional authority to the minister to detain any person without trial, the condition being that he has reasonable cause for the belief which leads to the detention order. The meaning, however, which for the first time was adopted by the Court of Appeal in the Greene case and appears to have found favour with some of your Lordships is that there is no condition, for the words “if the Secretary of State has reasonable cause” merely mean “if the Secretary of State thinks that he has reasonable cause.” The result is that the only implied condition is that the Secretary of State acts in good faith. If he does that – and who could dispute it or disputing it prove the opposite? – the minister has been given complete discretion whether he should detain a subject or not. It is an absolute power which, so far as I know, has never been given before to the executive, and I shall not apologize for taking some time to demonstrate that no such power is in fact given to the minister by the words in question.

In all these cases it is plain that unlimited discretion is given to the Secretary of State, assuming as everyone does that he acts in good faith.

I have pointed out that the words in question have a plain and natural meaning, that that meaning has been invariably given to them in statements of the common law and in statutes, that there has been one invariable construction of them in the courts, and that the Defence Regulations themselves clearly recognize that meaning, using different words where it is intended that the executive officer should have unqualified discretion…

If, then, the natural construction of the words indicates an objective condition to the power of the minister to detain, whose existence must, therefore, in case of dispute be cognizable by a court of law, what room is there for any other construction? I will deal with the suggested inconvenience to the minister or possible prejudice to the interests of the State later on…

I view with apprehension the attitude of judges who on a mere question of construction when face to face with claims involving the liberty of the subject show themselves more executive minded than the executive. Their function is to give words their natural meaning, not, perhaps, in war time leaning towards liberty, but following the dictum of Pollock C.B. in Bowditch v. Balchin , cited with approval by my noble and learned friend Lord Wright in Barnard v. Gorman :

“In a case in which the liberty of the subject is concerned, we cannot go beyond the natural construction of the statute.”

In this country, amid the clash of arms, the laws are not silent. They may be changed, but they speak the same language in war as in peace. It has always been one of the pillars of freedom, one of the principles of liberty for which on recent authority we are now fighting, that the judges are no respecters of persons and stand between the subject and any attempted encroachments on his liberty by the executive, alert to see that any coercive action is justified in law. In this case I have listened to arguments which might have been addressed acceptably to the Court of King’s Bench in the time of Charles I.
I protest, even if I do it alone, against a strained construction put on words with the effect of giving an uncontrolled power of imprisonment to the minister. To recapitulate: The words have only one meaning. They are used with that meaning in statements of the common law and in statutes. They have never been used in the sense now imputed to them. They are used in the Defence Regulations in the natural meaning, and, when it is intended to express the meaning now imputed to them, different and apt words are used in the regulations generally and in this regulation in particular. Even if it were relevant, which it is not, there is no absurdity or no such degree of public mischief as would lead to a non-natural construction.
I know of only one authority which might justify the suggested method of construction:
“‘When I use a word,’ Humpty Dumpty said in rather a scornful tone, ‘it means just what I choose it to mean, neither more nor less.’ ‘The question is,’ said Alice, ‘whether you can make words mean so many different things.’ ‘The question is,’ said Humpty Dumpty, ‘which is to be master – that’s all.'”
(“Through the Looking Glass,” c. vi.)
After all this long discussion the question is whether the words “If a man has” can mean “If a man thinks he has.” I am of opinion that they cannot, and that the case should be decided accordingly.

Of course, if the subjective theory is right and the Secretary of State has indeed unconditional power of imprisonment, it was enough for him to say that he exercised the power. But it seemed to be suggested in argument that, even if the power were conditional, yet it would be a good return by the Secretary of State to say that he had made the order in the terms of the regulation. This seems to me, with respect, to be fantastic. A minister given only a limited authority cannot make for himself a valid return by merely saying I acted as though I had authority. His ipse dixit avails nothing. A constable would make no valid return by saying: “I had reasonable cause for my arrest,” or “I served the criminal at the time with a written notice that I was arresting him for reasonable suspicion of felony.” However, on my view of this, the Secretary of State has made a return sufficient to indicate that the Divisional Court were right in refusing to order the writ to issue. I think that the appeal in this case.’

Edited and formatted for ease of reading. Matter in parentheses added.