ABSTRACT 

This paper delves into the historical evolution of insanity defence laws, tracing the journey from the McNaughton Rules to the contemporary framework embodied in Section 84 of the Indian Penal Code, 1860. “The McNaughton Rules, established in the early 19th century, laid the foundation for assessing criminal responsibility based on the defendant's mental state. Over time, societal perceptions of mental illness and legal standards for insanity have undergone significant transformations. The primary focus of this analysis is Section 84 of the Indian Penal Code, a crucial provision that addresses the question of criminal liability when an accused person claims insanity as a defence. Examining the language, interpretation, and judicial application of Section 84, the paper aims to elucidate the legal criteria for establishing insanity in the Indian context. This involves an exploration of case law, legal precedents, and scholarly discourse surrounding the implementation of Section 84. The paper also considers the broader implications of insanity defence laws on the criminal justice system, mental health policy, and societal attitudes towards individuals with mental disorders. It critically evaluates the balance between protecting society from potential harm and ensuring the fair treatment of individuals suffering from mental illnesses. Through a comparative analysis with international standards and practices, the paper assesses the strengths and weaknesses of Section 84, offering insights into potential areas for reform. Additionally, it explores the challenges faced by legal practitioners, mental health professionals, and policymakers in navigating the intricate intersection of law and psychiatry. By providing a comprehensive historical overview and contemporary analysis, this paper contributes to a nuanced understanding of the evolution of insanity defence laws and their implications for justice and mental health in the Indian legal system. It aims to stimulate discourse on potential reforms to ensure a more just and compassionate approach to individuals grappling with mental illness within the realm of criminal law.