Section 84 of the Indian Penal Code : “Act of a person of unsound mind.—Nothing is an offence which is done by a person who, at the time of doing it, by reason of unsoundness of mind, is incapable of knowing the nature of the act, or that he is doing what is either wrong or contrary to law.” This is a general defense under Indian Penal Code on pretext that one, who is insane and has no mind, cannot have the necessary mens rea to commit a crime. Hence, unsoundness of mind is often termed as Insanity. In layman words, Insanity is mental abnormality. Generally or medically, Insanity means a disorder of the mind which eradicates the reasoning capacity of a man, to such an extent as to render him incapable of understanding the nature and consequences of his acts. But to avail the defense of insanity legally, the tests of insanity need to be passed. Ø Test of Insanity From time to time many tests have been done for this purpose but the most acceptable of all time...