What is known as the principle that identifies the required degree of intent for various crimes?

The principle that identifies the required degree of intent for various crimes is referred to as mens rea. This Latin term translates to "guilty mind" and is fundamental to understanding criminal liability. Mens rea focuses on the mental state of the defendant at the time the crime was committed, determining their intent or knowledge regarding the illegal act.

Different crimes require different levels of mens rea, ranging from negligence to intentional acts. For example, some crimes, like murder, necessitate a specific intent to kill, while others may only require a reckless disregard for the consequences of one's actions. Understanding the specific mens rea associated with a crime is crucial, as it directly influences the charges brought and the potential defenses available.

In contrast to mens rea, actus reus refers to the actual physical act or conduct that constitutes a crime, while substantive law encompasses the body of law defining offenses and the punishment for them. Criminal intent, while an important concept, is more of an informal term that relates to mens rea but does not encapsulate the intricacies and classifications of intent required for different crimes. Thus, mens rea is the precise term that captures the principle of intent necessary for various crimes.