Actus Non Facit Reum Nisi Mens Sit Rea is a Latin maxim which means that an act to be illegal, the person should do it with a guilty mind. Conviction of a crime requires proof of a criminal act and intent. A crime generally consists of two elements, a physical, wrongful deed (the “actus reus”), and a guilty mind that produces the act (the “mens rea”). A crime ordinarily is not committed if the mind of the person doing the act is innocent This Latin phrase is often given as a pinnacle of the common law criminal justice system and was valued by jurists. It was an essential component to all criminal cases. However, the maxim is subject to many criticisms.