ABSTRACT
This chapter focuses on the following defences: dealing with a problem question by constructing the liability for a criminal offence and considers the availability of a potential defence. It considers the defence before examining the legal effect of the specific defence. The first defence is the defence of automatism and its elements of insanity are: defect of reason and cause a disease of the mind. The defect of reason causes a disease of the mind that establishes as an internal reason. It is the internal nature of the source of the defect of reason that separates insanity from the defence of non-insane automatism. The chapter considers a range of factors that are internal or external. It discusses the Intoxication that occur when a defendant consumes drugs or alcohol, used as a defence and in crimes of specific intent voluntary intoxication provides a defence where the mens rea is not formed.
