50th anniversary of the "Dutch Courage Rule"

Today marks the 50th anniversary of the House of Lords' decision in Attorney-General for Northern Ireland v Gallagher.  

In this case Gallagher and his wife had been married for 16 years during which time they frequently quarrelled, usually after he "had taken drink", and was on occasion violent towards her.  During a period in 1960 he was in and out of a mental hospital in Omagh.  During one of his periods of release he purchased a knife,  a bottle of Guinness and a bottle of Power's whisky. He went to his wife's house, drank most of the whisky, then brutally murdered his wife. When arrested by police he said: "I have no regrets: she gave me a hell of a life these past three years" and subsequently, having been cautioned, said: "I made up my mind to kill her about a fortnight or three weeks ago."

The issue in the case was delightfully summarised by Lord Denning:

"The man is a psychopath. That is, he has a disease of the mind which is not produced by drink. But it is quiescent. And whilst it is quiescent, he forms an intention to kill his wife. He knows it is wrong but still he means to kill her. Then he gets Himself so drunk that he has an explosive outburst and kills his wife. At that moment he knows what he is doing but he does not know it is wrong. So in that respect—in not knowing it is wrong—fee has a defect of reason at the moment of killing. If that defect of reason is due to the drink, it is no defence in law. But if it is due to the disease of the mind, it gives rise to a defence of insanity. No one can say, however, whether it is due to the drink or to the disease. It may well be due to both in combination. What guidance does the law give in this difficulty?"

The answer to that question, was as follows:

“My Lords, I think the law on this point should take a clear stand. If a
 man, whilst sane and sober, forms an intention to kill and makes preparation 
for it, knowing it is a wrong thing to do, and then gets himself drunk 
so as to give himself Dutch courage to do the killing, and whilst drunk 
carries out his intention, he cannot rely on this self-induced drunkenness 
as a defence to a charge of murder, nor even as reducing it to manslaughter.
  He cannot say that he got himself into such a stupid state that he was 
incapable of an intent to kill. So also when he is a psychopath, he cannot 
by drinking rely on his self-induced defect of reason as a defence of 
insanity.  The wickedness of his mind before he got drunk is enough to 
condemn him, coupled with the act which he intended to do and did do.
 A psychopath who goes out intending to kill, knowing it is wrong, and does
 kill, cannot escape the consequences by making himself drunk before doing 
it. ... . 
I would agree, of course, that if before the killing he had discarded his 
intention to kill or reversed it—and then got drunk—it would be a different
 matter. But when he forms the intention to kill and without interruption
 proceeds to get drunk and carry out his intention, then his drunkenness is 
no defence and none the less so because it is dressed up as a defence of
 insanity.”

Nowadays (and in England at the time, but not in Northern Ireland) Gallagher could have successfully raised a defence of diminished responsibility.