Early Implications of the Insanity Defense

(by Andrew Garofolo)

The early history of the insanity defense can be dated back as early as government. Even back in this period of history, many people viewed it as immoral to punish someone for a crime where they had no idea what they were doing was wrong at the time.

The first recorded usage of the insanity defense can be found in Hammurabi’s code which dates back to around 1772 BC. It used some sort of insanity defense (“Mental State Defense,” 2008).

In the days of the Roman Empire, the government found convicted people to be non-compos mentis, meaning without mastery of mind and not guilty for their criminal actions. (Borum & Fulero, 1999)

As time progressed, there have been some important phases of insanity defense before the emergence of the McNaughton.

  • First, there was the “good and evil” test. This test found its origins in biblical and religious concepts. Those who were seen as unable to distinguish between good and evil were considered insane. If the accused were able to distinguish between good and evil, they were found guilty of the crime.
  • The next major step in the insanity defense began with the emergence of the “wild beast test.” In the 1724 British case of “Rex vs. Arnold,” the judge ruled for the defendant to be acquitted by reason of insanity because he did not know what he was doing, and was doing no more than a “wild beast” would do. (Clark 1995).
  • In 1800, advancement was made in the insanity defense with Hadfield’s trial. Hadfield had fired a pistol at the King during a play. He had missed the target, but was still tried in court. Hadfield was charged with treason. He pleaded insanity (Eigen, 2004).

Up until this time, if a defendant was deemed not guilty by reason of insanity, the defendent would go free. In this particular trial if the defendant was under some sort of “delusion” during the time of the crime, they would be excused of their crime if the delusion was deemed true. He was found to be insane, and was acquitted. However, this led to the passing of the Criminal Lunatics Act of 1800 (Moran, 1985). This required a set procedure for defendants who were acquitted due to insanity. They were then required to be held in detention after trial until deemed okay to be released back into society.

  • In 1840, the standard for insanity was further clarified, by the case of Regina vs. Oxford. (Constanzo 2004). In this particular case, it was found that the defendant suffered from the effect of a “diseased mind,” and was “quite unaware of the nature, character, and consequences of the act he was committing.” This ruling redefined insanity, and set the stage for the major rules on insanity that were soon to come.
  • The following video has interesting insight on the insanity defense from Laurence Miller, Ph.D., author of “Criminal Psychology – Nature, Nurture, Culture”



Borum, R., & Fulero, S. (1999).  Empirical Research on the Insanity Defense and attempted reforms:  Evidence toward Informed Policy.  Law and Human Behavior, 23(3), 375-394.

Clark, R. (1995). Insanity and the Death Penalty. Capital Punishment UK. Retrieved from http://www.capitalpunishmentuk.org/biblio.html

Costanzo, M. (2004). Psychology Applied to Law.  Belmont, CA:Wadsworth/Thomson Learning

“Mental State Defense.” (2008). Forensic Psychological Services. Retrieved from: http://www.forensicpsychology.biz/Mental_State_Defense.aspx

Moran, R. (1985). The Origen of as a Special Verdict: The Trial for Treason of James Hadfield. Law and Society Review. 19, 487-519. Retrieved from: http://www.jstor.org/stable/3053574

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