The foundational elements of criminal law, actus reus and mens rea, are vague, imprecise, and indeterminate categories that are based on outdated notions about human behavior. These confused categories affect not only what legally constitutes choice, volition, and intent, but also the defendant's ability to present evidence (since the categories define the evidence that will be admissible), and ultimately, criminal liability. In this Article we explain how neuroscience allows us to reconsider these legal concepts and conceive a more informed view of human behavior (and therefore criminal liabilty). The Article explains how distortions in brain function affect the way people perceive reality and how that distortion affects their choices, volition, and intent. It proposes that a more expansive category, encompassing both foundational elements but with a more expanded definition of choice, volition, and intent, would enable judges to permit the mentally ill accused to present scientifically valid expert testimony about how their illness affects behavior so that the jury will be able to reach an informed decision.
Beecher-Monas, Erica and Garcia-Rill, Edgar
"Actus Reus, Mens Rea, and Brain Science: What Do Volition and Intent Really Mean?,"
Kentucky Law Journal: Vol. 106
, Article 5.
Available at: https://uknowledge.uky.edu/klj/vol106/iss2/5