One unfortunate fact of life is that, no matter how careful we are, accidents do happen. Everybody knows and has experienced this, but, on a deeper level, what actually makes it an accident? As we all (hopefully) know, an accident is when you are performing a task and something unintended happens. For the times when it isn’t an accident, this is where today’s word comes into use.
Here is a brief example: if you are washing glassware and several pieces fall to the floor and break, it is obviously an accident. (If you are deliberately juggling it before you drop it, that is actus reus, but we’ll save that for another day.) Now, let’s suppose that you didn’t like this glassware and wanted to buy new glasses, but you didn’t have the space to accommodate new pieces…. unless the old glassware breaks. This raises an issue of mens rea, which is Latin for ‘guilty mind’ and causes us to consider whether this action was actually an accident or, mentally, your intention was to break the glasses.
Understandably, this is a rather simplistic explanation, but, at the heart of actual criminal law, mens rea is the aspect of intention and planning of an action – the mental side of a crime. Before the 1600s, common law in the English-speaking world largely judged people solely by the criminal act that they were accused of committing, which likely led to a number of people being wrongfully punished; however, along with the beginning of the Age of Enlightenment, legal authorities began taking account of a person’s state of mind in relation to the crime they had allegedly committed. This is where we begin seeing different sentencing requirements based on state of mind, such as (in modern day) a charge of murder being assigned to those with mens rea and a lesser charge of manslaughter being assigned to those without mens rea.
Though the phrase has long been known in Latin from the common-law precept – Actus non facit reum nisi mens rea sit, meaning “the act does not make a person guilty unless the mind is also guilty”- the shortened form is relatively new in English. Surprisingly, the first mention of it comes from an 1861 work entitled Crown Cases Reserved for Consideration by Edwin Chandos Leigh and Lewis William Cave, which states that: “The mens rea is an essential ingredient in every offence.” In the years since then, we have also seen our understanding change to the point where there are now varying degrees of mens rea depending on the situation; however, one thing to always remember is that, when it comes to crime, don’t even think about it.