Assertion (A): For any crime to exist, the physical element of crime needs to be complemented by the mental element.
Reasoning (R): Causing injury to an assailant in self-defense is a crime in Indian criminal jurisprudence.

A is correct but R is false.

Therefore for any crime to exist, the physical element of crime needs to be complemented by the mental element. The concept of mens rea evolved in England th during the 17 Century. During this period, the judges began to hold that an act alone could not create criminal liability unless it was accompanied by a guilty state of mind. Causing injury to an assailant in self-defense is not a crime, but the moment injury is caused with intent to take revenge, the act becomes criminal.