The Province of Mental Impairment in Victoria: An Analysis of the Conflict between Stiles and Hawkins and a Prediction about How It Will Be Resolved

The defence of mental impairment is the modern expression of the common law defence of insanity. Recently, a difficult question has emerged about the process of proof in mental impairment cases. The problem arises when an accused person claims they have a defence of mental impairment but also claims they did not possess the intent required for the particular crime. The law regarding how to direct juries where both mental impairment and lack of intent are in issue is unsatisfactory. The issue raises fundamental questions of criminal law theory. This article examines the conflict between the ‘linear’ approach the Victorian Court of Appeal adopted in R v Stiles (‘Stiles’) and the ‘non-linear’ approach the High Court took in the decision of Hawkins v The Queen. It examines the problem in light of several criminal law theories. It concludes that the conflict is likely to be resolved by a process of statutory construction and that the approach in Stiles is likely to prevail.