Intoxication is a case-by case defence so it can be fit for purpose.
The legal principle suggest that there is a defence for criminals who have impaired thinking due to alcohol, drugs, and other substances.
Public policy reasons makes the defence restrictive and an easy excuse for criminality.
There are complicated divisions in law which can cause problems like specific and basic intent in voluntary intoxication.
Intoxication is not a "true defence" as it applies, if the defendant has no mens rea then they are missing one basic element of a crime.
Voluntary intoxication is the defendant choosing to be in that position.
Sheehan and Moore: Drunk intent is still intent.
For specific intent crimes like murder, theft, and s18 GBH, the liability can drop to a lesser crime.
In Lipman, there was nomensrea for murder so they dropped the charge to manslaughter.
However, theft has no lesser crime which can be problematic and makes the law inconsistent.
Few crimes require specific intent so it doesn't help much
In crimes of basic intent, the law is clear and there is no defence.
In Majewski, the combination of drinks and drugs led to them committing several basic intent offences. Recklessness was enough because Majewski voluntarily took the drink and drugs.
Intoxication is seen as an aggravating factor.
Gallagher: Dutch courage. Having intent before getting intoxicated.
Involuntary intoxication occurs through no fault of the defendant and is a complete defence, making it very tight and hard to succeed with.
The case of Kingston highlights inconsistency.
Kingston said he was involuntarily drunk because his drink was spiked. He was convicted as the assault was intentional (drunk intent is still intent), a public policy argument.
However, in Kingston's case, the Court of Appeal overruled that and said it wasn't his fault he was drunk due to the spiking, a legal principle argument.
Kingston's case was again passed on and the HL restored the conviction saying that public policy was key. This shows that different court levels can have different views.
The Butler Committee recommended an offence of dangerous intoxication whilst others say intoxication should be no defence and just dealt with in sentencing.
Alcohol costs the NHS lots of money but huge revenue is generated by taxes and the licensing industry has strong lobbying powers.
Critics say it would be hard to create a workable statute so what already exists is goodenough.
The judiciary only occasionally say that the intoxication laws should be reformed.
The law probably need reform, but it is perhaps noturgent and unlikely to happen in practice.