ABSTRACT
This chapter explains the law on insanity and automatism, intoxication. The law on insanity is laid down in the M'Naghten Rules. Defendant (D) must prove that he had a 'defect of reason', from a 'disease of the mind', so that he did not know the 'nature and quality' of his act or that it was 'wrong'. 'Wrong' means legally wrong. If the defence succeeds D receives the 'special verdict' which is a form of qualified acquittal – D may be hospitalised or made subject to other orders. There are two types of intoxication: voluntary and involuntary. With voluntary intoxication, D may have a defence to 'specific intent' crimes only, such as murder, theft and robbery, provided D lacks the necessary mens rea, but D will not have a defence to crimes of 'basic intent', such as assault, ABH, GBH, rape and manslaughter. Involuntary intoxication is potentially a defence to all crimes, but again only if D lacks mens rea.
