Re-examining Miller v Miller: a search for rationality and coherence in Australia's illegality defence

While it has long been accepted that a 'confirmed criminal is as much entitled to redress as his most virtuous fellow citizen',1 the defence of illegality has the potential to entirely divest plaintiffs of private law remedies. In light of the anomalous approach to the illegality defence adopted by the High Court of Australia in Miller v Miller, this article considers whether Australia's illegality defence in the general law of torts requires reformulation. In adopting a comparative approach, the article demonstrates that although Australia's duty-based illegality defence is criticised for being unusual and indeed unjust, the discretionary-based approach implemented within the United Kingdom is denounced as 'intolerably uncertain' and the rule-based approach formulated in Canada is condemned for its narrow scope and rigidity. In seeking to propose a future direction for the development of Australia's illegality defence in the context of tort law, this article articulates and deploys a legal coherence framework within which the various formulations of the illegality defence can be appraised.