Metaphysics of the Guilty Mind: A Critical Reevaluation of the Doctrine of Mens Rea

Abstract

Actus reus non facit reum nisi mens sit rea (“an act is not culpable unless the mind is guilty”) is a maxim represented in some form in most modern legal systems. It is “a sacred principle of criminal jurisprudence that the intention to commit the crime is the essence of the crime”. To our modern framing of morality, this seems fairly intuitive. Mens rea (“the state of mind or inattention that, together with its accompanying conduct, the criminal law defines as an offense” – Latin for “guilty mind”) is thus required to be shown in the vast majority of criminal cases. However, a critical reevaluation of the doctrine reveals not just concerning weak justifications for the doctrine’s implementation, but inseparable ties between the doctrine and the racialized system of violent incarceration and imperialism it developed to facilitate.

First, a survey of its historical origins casts doubts on the universality of criminal systems operating under this framework and contextualizes the maxim in its current form as a product of Christian theology and its institutionalization within imperial British law. Drawing on historical archives and works of legal history, I trace the doctrine from its surprisingly recent origins to its formalization in the U.S. Model Penal Code in 1962 and explore the violent systems of oppression it arose from and the problematic worldview it prescribes.

Second, to meet the doctrine as it is, I conduct an examination of the potential philosophical justifications for the doctrine in its present state. I identify three broad categories of metaphysical accounts for what mens rea is offered in available literature:

(1) An inherent property, which is further broken down into two sub-categories. The first is what I call soul alteration – that at the time of a guilty act, the perpetrator’s soul gains a property; this is the metaphysical account that religious thinkers like St. Augustine would have been supportive of. The second is that mens rea is truly separated from moral accountability, and that we ought to think of it as a factual determination of whether one held a specific brain state during the commission of an unlawful act. The second is much more compelling in modern times, and the account that I would wager is predominant among jurists, but I will argue that this is a disastrous misunderstanding of the nature of the human mind and decision-making.

(2) A mental breach of moral duty, where I consider both Kantian & Utilitarian justifications. Strains of both Kantian and utilitarian ethics derive objective moral rules from rational arguments. Here, the theory of mens rea is an evaluation of whether the perpetrator had a mental state in conflict with rational moral law. For opposite reasons, both accounts fail to provide a reasonable justification for the legal existence of mens rea.

(3) A useful social construct. Several formal sources justify mens rea as “merely a convenient label” and rely on practical needs within our modern justice system. I evaluate these reasons and ultimately conclude that while mens rea is indeed a useful social construct, it is one that is useful exclusively for perpetuating injustice. I also explore its connections to racial pseudo-science.

Finally, I look to reimagine what a legal system without mens rea could look like. I pull from past and current indigenous groups who practice non-carceral systems of community justice, as well as corners of institutionalized criminal law that operate through “strict liability” — crimes without mental requirements