Difference between Mens Rea & Actus Reus

Mens rea and actus reus are two essential elements of a crime.

Actus reus refers to the physical act or omission that constitutes a criminal offense (e.g., theft, assault).

Mens rea is the mental intent or guilty mind behind that act (e.g., intention, knowledge, recklessness).

For criminal liability to arise, both must usually coexist—this is known as the concurrence principle. For instance, in State of Maharashtra v. M.H. George (1965 AIR 722), the Supreme Court stressed the need for guilty intent. Under the IPC, sections like 299 (culpable homicide) combine both elements. Without mens rea, an act by itself may not constitute a crime.